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Sorption-based atmospheric water harvesting (SAWH) shows great promise to mitigate the worldwide water scarcity, especially in the arid regions. Salt-based composite materials are the extensively used sorbents for SAWH, however, they suffer from complex preparation to avoid salt leakage. Furthermore, the significant amount of heat produced during water harvesting process is often neglected and wasted. Herein, an integrated strategy is developed to synthesis salt-based stable super moisture-sorbent sponge by using the chelation of LiCl and dopamine (DA), and the simultaneous polymerization of DA on melamine sponge (PMS). The as-prepared LiCl/PMS/CNTs showed high water uptake, reaching 1.26 and 1.81 g g -1 at 15% and 30% RH, respectively, and no salt leakage is observed during the water absorption process. Remarkable daily water production of 3.47 kg kg -1 day -1 in an arid environment (30% RH) is achieved. Moreover, a dual-function system is successfully constructed by combining the LiCl/PMS/CNTs with a thermoelectric module to fully utilize the heat generated from the SAWH process, which can realize the simultaneous production of fresh water and electricity. The maximum output power density is up to 35.4 and 454.4 mW m -2 during the water absorption and desorption process, respectively., (© 2024 Wiley‐VCH GmbH.)

Management of carbon emissions of regional electricity generation involves resolving much nuanced relationships. However, current studies pertaining to the relationship between energy and the economy utilize only quarterly and annual data and focus on the long-run relationship but are oblivious to temporal associations. This study takes the context of the State of Texas and utilizes per 15 min of data between 2007 and 2020 to derive the monthly time series of life-cycle emissions, emissions factor, and energy generation. The study also divides each day into three portions (0:00-8:00, 8:00-16:00, and 16:00-24:00) in order to descend precision down to the hourly level. Impulse-response analysis indicates that (1) employment conditions impact emissions by affecting the amount of electric energy generated, while demographic (population as reflected by property price) tends to impact emissions by affecting the carbon intensity of electricity, and (2) the emissions produced during 0:00-8:00 display different reaction to fluctuation of regional economic conditions compared to emissions produced during other periods, the effect emanates from either energy generation fluctuation or emissions factor shocks. The broader implication of the findings lies in an emphasis on time-interval-specific analysis and concurrent consideration of both energy generation and emissions factors that can lead to optimized policy implementation results., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Water evaporation-induced electricity devices (WEDs) have become extremely attractive, converting ambient heat into electricity while being environmentally friendly. However, most current WEDs are costly and cumbersome to fabricate, which greatly limits their commercialization process. Here, we present WEDs based on starch cross-linked with glass fiber filter paper (Starch-GF). A single device produced an open-circuit voltage of 0.3 V, a short-circuit current of 1.2 μA, and a maximum power density of 1.8 mW/m 2 in a natural environment under 24 h of continuous measurements. Starch-GF devices can drive electronics after charging capacitors and have environmentally friendly properties. This research contributes significantly to the discovery of hydrovoltaic materials and their practical implementation in hydrovoltaic devices.

This paper employs a new framework based on internationally available indicators to conduct a comparative analysis of electricity generation among Latin American and Caribbean (LAC) countries, using data from 2021, the most recent available. Two multivariate techniques, cluster analysis and factor analysis, are used in this study. In recent years, electricity generation in the region has increased significantly, largely driven by the economic growth of these nations. A notable trend is the rising contribution of renewable energy sources, which accounted for 55 % of total generation in 2021, thanks to the region's exceptional climatic and geographic conditions. However, the absence of overarching supranational policies has led to significant disparities in energy strategies across these countries, both in design and implementation. Among the 20 LAC countries studied, 35 % do not reach a 50 % share of sustainable electricity generation. Understanding how these countries group regarding sustainable electricity generation is essential for identifying their key characteristics. The analysis yields three fundamental conclusions: first, the selected indicators are highly effective in achieving the study's objectives; second, the principal differences between the identified groups are largely influenced by each country's level of development and reliance on renewable energy sources; and third, from a policy perspective, there is a clear need for a supranational framework to support the national efforts and strategies being independently pursued by these countries, particularly regarding the design and implementation of energy policies. This paper contributes to bridging the gap in the international academic literature concerning sustainable electricity generation in LAC region, and it aligns with studies focused on the analysis of renewable energy sources and sustainable development., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Hexavalent chromium (Cr (VI)) and para-chlorophenol (4-CP) are prevalent industrial wastewater contaminants that are recalcitrant to natural degradation and prone to migration in aquatic systems, thereby harming biological health and destabilizing ecosystems. Consequently, their removal is imperative. Compared to conventional chemical treatment methods, CW-MFC technology offers broader application potential. Leersia hexandra Swartz can enhance Cr (VI) and 4-CP absorption, thereby improving wastewater purification and electricity generation in CW-MFC systems. In this study, three CW-MFC reactors were designed with L. hexandra Swartz in distinct configurations, namely, stacked, multistage, and modular, to optimize the removal of Cr (VI) and 4-CP. By evaluating wastewater purification, electrochemical performance, and plant growth, the optimal influent hydraulic retention time (HRT) was determined. The results indicated that the modular configuration at an HRT of 5 days achieved superior removal rates and power generation. The modular configuration also supported the best growth of L. hexandra , with optimal photosynthetic parameters, and physiological and biochemical responses. These results underscore the potential of modular CW-MFC technology for effective detoxification of complex wastewater mixtures while concurrently generating electricity. Further research could significantly advance wastewater treatment and sustainable energy production, addressing water pollution, restoring aquatic ecosystems, and mitigating the hazards posed by Cr (VI) and 4-CP to water and human health.

Solar-powered interfacial water evaporation is a promising technique for alleviating freshwater stress. However, the evaporation performance of solar evaporators is still constrained by low photothermal conversion efficiency and high water evaporation enthalpy. Herein, 0D carbon quantum dots (CQDs) are combined with 2D MXene to serve as a hybrid photothermal material to enhance the light absorption and photothermal conversion ability, meanwhile sodium carboxymethyl cellulose (CMC)/polyacrylamide (PAM) hydrogels are used as a substrate material for water transport to reduce the enthalpy of water evaporation. The synergistic effect in 0D CQDs/2D MXene hybrid photothermal materials accelerate the carrier transfer, inducing efficient localized surface plasmon resonance (LSPR) effect. This results in the enhanced photothermal conversion efficiency. The integrated hydrogel evaporators demonstrate a high evaporation rate (1.93 and 2.86 kg m -2  h -1 under 1 and 2 sunlights, respectively) and low evaporation enthalpy (1485 J g -1 ). In addition, the hydrogel evaporators are applied for photothermal sensing and temperature difference power generation (TEG). The TEG device presents an efficient output power density (230.7 mW m -2 ) under 1 sunlight. This work provides a feasible approach for regulating and controlling the evaporation performances of hydrogel evaporators, and gives a proof-of-concept for the design of multipurpose solar evaporation systems., (© 2024 Wiley‐VCH GmbH.)

Resourceful treatment of wastewater is a promising way to facilitate sustainable development. Recently, photocatalytic fuel cells (PFCs) have attracted widespread attention as the method that can synchronously achieve wastewater treatment and clean energy production only depend on light. However, few PFCs focused on treating complex uranium (U(VI))-organic wastewater. This study prepared a SnS 2 nanoplate decorated carbon felt (SnS 2 /CF) material by facile hydrothermal method and used as the cathode to construct a hybrid tandem photocatalytic fuel cell (HTPFC) system. Compared to the CF-HTPFC, the removal efficiencies of U(VI) and tetracycline hydrochloride (TCH) increased to 3.4 and 1.8 times in the SnS 2 /CF-HTPFC system, accompanied with the reaction rate (k obs ) values increased to 30.39 and 3.78 times, respectively. More importantly, under real sunlight irradiation (From 10:00 to 16:00), the removal efficiencies of U(VI) and TCH respectively reached 92.49 % and 97.96 %, and the P max reached 6.49 mW·cm -2 . HTPFC also displayed satisfactory performances in treating radioactive wastewater containing different organic compounds, with the removal efficiencies of U(VI) and organic compounds both exceeded 93.35 %. The loading of SnS 2 nanoplates enhanced electrochemical performance and introduced abundant S active sites, allowing more U(VI) to be adsorbed and reduced, and simultaneously promoting the removal of organic matter by improving the charge separation efficiency., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Photocatalytic fuel cells (PFCs) present a promising and environmentally friendly approach to simultaneously treat organic pollutants in wastewater and electricity generation. The development of photoanodes with high light absorption and carrier mobility is essential for enhancing the performance of PFCs but remains challenging. Herein, a one-step self-assembly strategy was adopted to develop flower-like WO 3 /rGO microspheres for PFC devices. Attributed to the abundant surface-active sites, enhanced light harvesting, and efficient separation of photogenerated charge carriers, the WO 3 /rGO photoanode demonstrated superior rhodamine B (RhB) degradation rate (90% in 2 h), maximum power density (4.74 μW/cm 2 ), and maximum photocurrent density (0.096 mA/cm 2 ), 1.4, 2.4, and 4.0 times higher than the corresponding pure WO 3 photoanode, respectively. Density functional theory (DFT) calculations reveal that the built-in electric field formed between the interface of WO 3 and rGO promotes the transfer of photogenerated electrons from WO 3 to rGO, thus exerting a significant impact on improving the migration and separation of photoinduced charge carriers. Moreover, by combining experimental and theoretical results, a complete PFC operation mechanism for the PFC system was proposed. This study focuses on the strategy of constructing rGO-doped photocatalysts to enhance the interfacial charge transfer mechanism, providing a promising approach for the development of high-performance photoanodes in PFC systems.

Extreme temperature variations are a problem that must be faced in the practical application of microbial fuel cells (MFCs), but MFCs are not extensively described for low and even freezing temperatures. This study assessed the effect of low-temperature shock on the power generation performance and microbial community structure of MFCs. Two scales of MFCs, the small (mL-MFC) and the large (L-MFC), were constructed in the laboratory and their performance was evaluated before and after freezing at -18 °C. The experimental results demonstrate that both MFCs were capable of rapidly restoring their voltage to the previous level after thawing. For the mL-MFC (rGO/Ag), the power density recovered from 194.30 ± 10.84 mW/m 2 to 195.57 ± 4.02 mW/m 2 after thawing. For L-MFC (carbon felt electrodes), the power density increased significantly from the initial 1.79 mW/m 2 to 173.90 mW/m 2 after thawing, but the performance degradation problem after reactor amplification still needs to be solved. The sediment microbial fuel cell (SMFC) was successfully constructed and operated in a natural outdoor environment to maintain high voltage output after the period of frost. Microbial analysis indicated after the frost period, psychrotolerant microorganisms enriched on the anode, such as Flavobacterium and Psychrobacter, while the relative abundance of anaerobic methanogenic bacterium decreased. Overall, freeze-thaw operations had a non-negative impact on the performance of MFCs and provided some references for their practical applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, a microbial fuel cell was constructed using Raoultella sp. XY-1 to efficiently degrade tetracycline (TC) and assess the effectiveness of the electrochemical system. The degradation rate reached 83.2 ± 1.8 % during the 7-day period, in which the system contained 30 mg/L TC, and the degradation pathway and intermediates were identified. Low concentrations of TC enhanced anodic biofilm power production, while high concentrations of TC decreased the electrochemical activity of the biofilm, extracellular polymeric substances, and enzymatic activities associated with electron transfer. Introducing electrogenic bacteria improved power generation efficiency. A three-strain hybrid system was fabricated using Castellaniella sp. A3, Castellaniella sp. A5 and Raoultella sp. XY-1, leading to the enhanced TC degradation rate of 90.4 % and the increased maximum output voltage from 200 to 265 mV. This study presents a strategy utilizing tetracycline-degrading bacteria as bioanodes for TC removal, while incorporating electrogenic bacteria to enhance electricity generation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Direct lignin fuel cells (DLFC) are one of the important forms of high value-added utilization of lignin. In this study, lignin was studied not only as a fuel but also as a catalyst. Specifically, Kraft lignin was modified with ZnCl 2 , KOH and THF (Tetrahydrofuran) respectively, and added to the catalyst after activation. The results of scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectrometer (EDS), Brunauer - Emmett - Teller (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectra shown that AL/FePc-NrGO (activated lignin/iron phthalocyanine/nitrogen-doped reduction of graphene oxide) three-dimensional composite catalyst has been synthesized. The results showed that KOH-activated Kraft lignin had the best performance as an oxygen reduction reaction (ORR) catalyst, with a half-wave potential (E 1/2 ) of 0.73 V and a limiting diffusion current density of 4.3 mA cm -1 . The THF-modified catalyst showed similar stability and methanol resistance to 20 % Pt/C at ORR. The ORR catalyst applied to the DLFC has the best electrical performance with an open circuit voltage (OCV) was 0.53 V and the maximum power density it could reach 95.29 mW m -2 when the catalyst was modified with THF. It is encouraging that the AL/FePc-NrGO catalyst has better-generated electricity performance than 20 % Pt/C. This work has provided a new idea for developing non-noble metal catalysts and studying direct biomass liquid fuel cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

In this study, the electric energy harvesting capability of the hierarchical pore gradient silica aerogel (HPSA) is demonstrated due to its unique porous structure and inherent hydroxyl groups on the surface. Taking advantage of the positively charged surface of unwashed HPSA credited by the preparation strategy, poly(4-styrene sulfonic acid) (PSS) can be spontaneously adsorbed onto unwashed HPSA and shows gradient distribution due to the pore-gradient structure of HPSA. By virtue of the gradient distribution and the stronger ionization of PSS, PSS-modified HPSA (PSS-HPSA) shows enhanced electricity generation performance from natural water evaporation with an average output voltage of 0.77 V on an individual device. The water evaporation-induced electricity property of PSS-HPSA can be maintained in the presence of a low concentration of salt. The desirable salt resistance capability benefits from the unique 3D hierarchical porous structure of HPSA which ensures rapid water replenishment so as to effectively avoid the salt accumulation. The HPSA-based devices with the advantages of unique porous structure, easy functionalization, good physicochemical stability, good salt resistance capability, and eco-friendliness show great potential as water evaporation-induced electricity generators.

Globally, nutrient pollution is a serious and challenging concern. Wastewater treatment plants (WWTPs) are designed to prevent the discharge of contaminants resulting from anthropogenic sources to the receiving water bodies. In this study, seasonal nutrient pollution load, and biological nutrient removal efficiency of an anoxic aerobic unit based WWTP were investigated. Seasonal assessment revealed that the average total nitrogen removal efficiency and total phosphorus removal efficiency of the WWTP do not meet the discharge standard of 10 mg/L and 1 mg/L, respectively. Furthermore, the WWTP does not utilize the energy contained in the wastewater. In this regard, dual chamber MFC (D-MFC) has emerged as a promising solution that can not only treat wastewater but can also convert chemical energy present in the wastewater into electrical energy. However, higher N O 3 - (57 ± 4 mg/L) and P-P O 4 3- (6 ± 0.52 mg/L) concentration in cathodic effluent is a major drawback in D-MFC. Therefore, to solve this issue, D-MFC was transformed into a microbial nutrient recovery cell (MNRC) which demonstrated a final N H 4 + -N and P-P O 4 3- , thus indicating MNRC is an eco-friendly, energy-neutral, and promising technology for electricity generation and recovering nutrients.4 + -N and P-P O 4 3- recovery up to 74 % and 69 %, respectively in the recovery chamber. Besides, MNRC attained a maximum power density of 307 mW/m 3 and a current density of 1614 mA/m 3 , thus indicating MNRC is an eco-friendly, energy-neutral, and promising technology for electricity generation and recovering nutrients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Sediment microbial fuel cells (SMFCs) generate bioelectricity from benthic sediments and thus providing both bioelectricity generation and sediment remediation. However, the high internal resistance of the cathode leads to a low power output, which requires research on cathode treatment. In this study, we explored the influence of light irradiation on bioelectricity production and nutrient removal in the SMFC system. The microcosm experiment of the SMFC system was designed with artificial illumination of 500 lux (light-SMFC) and compared with dark conditions of 15 lux (dark-SMFC), which showed that the current increases during photoperiods. The study reveals that light-illuminated SMFC consistently produced the highest voltage, with the highest voltage (553 mV) being 1.3 times higher than the dark-SMFC (440 mV). The polarization curves show a significant reduction in internal cathodic resistance under light condition, resulting in increased voltage generation. The light-SMFC exhibits the highest maximum power density of 35.93 mW/m 2 , surpassing the dark SMFC of 31.13 mW/m 2 . It was found that light illumination in the SMFC system increases oxygen availability in the cathodic region, which supports the oxygen reduction reaction (ORR) process. At the same time, the high bioelectricity output contributes to the highest sediment remediation by greatly reducing the chemical oxygen demand (COD) and phosphate (PO 4 -P) concentrations. The study highlights the potential of light illumination in mitigating cathodic limitation to improve SMFC performance and nutrient removal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Anoxygenic phototrophic bacteria is a promising catalyst for constructing bioanode, but the mixed culture with non-photosynthetic bacteria is inevitable in an open environment application. In this study, a Rhodopseudomonas-dominated mixed culture with other electrogenic bacteria was investigated for deciphering the differentiated performance on electricity generation in light or dark conditions. The kinetic study showed that reaction rate of OM degradation was 9 times higher than that under dark condition, demonstrating that OM degradation was enhanced by photosynthesis. However, CE under light condition was lower. It indicated that part of OM was used to provide hydrogen donors for the fixation of CO 2 or hydrogen production in photosynthesis, decreasing the OM used for electron transfer. In addition, higher COD concentration was not conducive to electricity generation. EIS analysis demonstrated that higher OM concentration would increase Rct to hinder the transfer of electrons from bacteria to the electrode. Indirect and direct electron transfer were revealed by CV analysis for light and dark biofilm, respectively, and nanowires were also observed by SEM graphs, further revealing the differentiate performance. Microbial community analysis demonstrated Rhodopseudomonas was dominated in light and decreased in dark, but Geobacter increased apparently from light to dark, resulting in different power generation performance. The findings revealed the differentiated performance on electricity generation and pollutant removal by mixed culture of phototrophic bacteria in light or dark, which will improve the power generation from photo-microbial fuel cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Water evaporation-induced electricity generators (WEGs) are regarded as one of the most promising solutions for addressing the increasingly severe environmental pollution and energy crisis. Owing to the potential carbon emission in the preparation process of WEGs, whether WEG represents a clean electricity generation technology is open to question. Here, a brand-new strategy is proposed for manufacturing negative carbon emission WEG (CWEG). In this strategy, the microalgae film is used as the electricity generation interface of WEG, which achieves a stable open-circuit voltage (V oc ) of 0.25 V and a short-circuit current (I sc ) of 3.3 µA. Since microalgae can capture carbon dioxide during its growing process, CWEG holds great promise to generate electricity without carbon emissions in the full life cycle compared with other WEGs. To the best of the author's knowledge, this is the first work using microalgae films to fabricate WEG. Therefore, it is believed that this work not only provides a new direction for designing high-efficiency and eco-friendly WEG but also offers an innovative approach to the resource utilization of microalgae., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

Power sector and energy systems models are widely used to explore the impacts of demographic, socio-economic or policy changes on the cost and emissions of electricity generation. Technology cost and performance data are essential inputs to such models. Despite the ubiquity and importance of these parameters, there is no standardised database which collates the variety of values from across the literature, so modellers must collect them independently each time they populate or update model inputs, leading to duplicated efforts and inconsistencies which can profoundly influence model results. Technology cost and performance varies between countries, regions and over time, meaning that data must be country- or region-specific and frequently updated. Values also vary widely between sources, so obtaining a broad consensus view is critical. Here, we present a database which collates historical, current, and future cost and performance data and assumptions for the six most prominent electricity generation technologies; coal, gas, hydroelectric, nuclear, solar photovoltaic (PV) and wind power, which together accounted for over 92 % of installed generation capacity in 2022. In addition, we provide the same data for utility-scale battery energy storage systems (BESS), regarded as critical to the integration of variable renewables such as wind and solar PV. The data are global in scope but with regional and national specificity, covers the years 2015 through to 2050, and span 5518 datapoints from 56 sources. The database enables modellers to select and justify model input data and provides a benchmark for comparing assumptions and projections to other sources across the literature to validate model inputs and outputs. It is designed to be easily updated with new sources of data, ensuring its utility, comprehensiveness, and broad applicability in future., (© 2024 The Author(s).)

This study evaluates the performance dynamics of Oman's principal part of electricity generation. Emphasis is placed on capturing the influence of the COVID-19 pandemic on the industry's performance indicators. We utilised the Malmquist Index method to analyse the changes in overall performance indicators over time. This approach allows us to distinguish between efficiency and technology changes. In addition, we employed the analysis of variance approach to test hypotheses related to COVID-19. Data is collected from twelve electricity producers across Oman's power sector. These consist of companies listed on the Stock Exchange Market in Oman, accounting for about 60 % of the total electricity production in the Sultanate. The predominant findings indicate that COVID-19 detrimentally impacted the sector's aggregate performance in 2020 but had a swift recovery in 2021. The analysis of the sample firm's productivity indices verifies that the decline in productivity in 2020 due to the Pandemic is attributable to a decrease in average efficiency indices and a negative shift in the projected frontier. These are probable consequences of the recessionary effects caused by the Pandemic. Despite a considerable decrease in average efficiency scores, a positive change in the frontier has facilitated a rapid recovery in 2021. This recovery can be attributed to the implementation of advanced technical upgrades in particular enterprises, which began as early as 2018/2019, well before the onset of the Pandemic., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Introduction: A radical shift in energy production is underway worldwide, replacing fossil fuels with renewable sources and causing structural changes in power generation systems., Problem Statement: Photovoltaic installations for self-consumption have experienced a steep increase in recent years. They have reached a significant installed capacity to cause a noticeable reduction in consumption from the national grid, which can cause serious management problems., Objectives: In this work, the evolution of the Spanish demand in the last years is analyzed to identify the influence of self-consumption in the overall demand. In addition, a mathematical model is defined to estimate this influence., Methodology: The demand curves of equivalent days in years with high and low installed self-consumption photovoltaic systems have been compared. Then, an estimation of the electricity generated with this source is proposed, with a mathematical model that takes into account data on solar radiation, installed photovoltaic power for self-consumption and other relevant factors., Results: The analysis of the demand has shown a significant reduction of the electricity demand in daylight hours when the number of self-consumption photovoltaic systems increases. Moreover, the proposed model has been able to provide an estimation of the electricity generated with this source. The addition of these estimates to the actual consumption curves of years with a high number of self-consumption installations gives profiles close to those obtained when self-consumption was low., Recommendation: New storage systems need to be implemented and grid management need to be improved to take advantage of the surpluses produced by photovoltaic systems., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

In the present study, the potential of Pseudomonas citronellolis 620C strain was evaluated, for the first time, to generate electricity in a standard, double chamber microbial fuel cell (MFC), with oily wastewater (OW) being the fuel at 43.625 mg/L initial chemical oxygen demand (COD). Both electrochemical and physicochemical results suggested that this P. citronellolis strain utilized efficiently the OW substrate and generated electricity in the MFC setup reaching 0.05 mW/m 2 maximum power. COD removal was remarkable reaching 83.6 ± 0.1%, while qualitative and quantitative gas chromatography/mass spectrometry (GC/MS) analysis of the OW total petroleum and polycyclic aromatic hydrocarbons, and fatty acids revealed high degradation capacity. It was also determined that P. citronellolis 620C produced pyocyanin as electron shuttle in the anodic MFC chamber. To the authors' best knowledge, this is the first study showing (phenazine-based) pyocyanin production from a species other than P. aeruginosa and, also, the first time that P. citronellolis 620C has been shown to produce electricity in a MFC. The production of pyocyanin, in combination with the formation of biofilm in the MFC anode, as observed with scanning electron microscopy (SEM) analysis, makes this P. citronellolis strain an attractive and promising candidate for wider MFC applications., (© 2024. The Author(s).)

This study investigates the low-temperature hydrogen plasma treatment approach for the improvement of hydrogen generation through waste aluminum (Al) reactions with water and electricity generation via proton-exchange membrane fuel cell (PEM FC). Waste Al scraps were subjected to ball milling and treated using two different low-temperature plasma regimes: Diode and magnetron-initiated plasma treatment. Hydrolysis experiments were conducted using powders with different treatments, varying molarities, and reaction temperatures to assess hydrogen generation, reaction kinetics, and activation energy. The results indicate that magnetron-initiated plasma treatment significantly enhances the hydrolysis reaction kinetics compared to untreated powders or those treated with diode-generated plasma. Analysis of chemical bonds revealed that magnetron-initiated hydrogen plasma treatment takes advantage by promoting a dual procedure: Surface cleaning and Al nanocluster deposition on top of Al powders. Moreover, it was modeled that such H 2 plasma could penetrate up to 150 Å depth. Meanwhile, electricity generation tests demonstrate that only 0.2 g of treated Al powder can generate approximately 1 V for over 300 s under a constant 2.5 Ω load and 1.5 V for 2700 s with a spinning fan., Competing Interests: Authors Rauan Meirbekova and Gudmundur Gunnarsson were employed by the company IceTec. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

In light of the efforts to ensure carbon neutrality by combating climate-related problems, the study investigates the effectiveness of electricity generation (EG) from the main renewable sources (hydro-HEG, solar-SEG, and wind-WEG). In this context, the study examines the countries of the Global South (i.e., Brazil, China, and India), considers EG at a disaggregated level and sectoral CO 2 emissions, applies nonlinear methods, and uses daily data between January 2, 2019 and December 31, 2022. The results demonstrate that (i) disaggregated EG sources have a stronger (weaker) time and frequency dependency on sectoral CO 2 emissions in China (Brazil and India); (ii) HEG has a stimulating impact on sectoral CO 2 emissions in all countries; (iii) SEG has an increasing impact on sectoral CO 2 emissions in Brazil and China, while it provides a decrease in sectoral CO 2 emissions in India; (iv) WEG upsurges sectoral CO 2 emissions in China, while it achieves a CO 2 reduction in Brazil and India; (v) disaggregated level EG has a causal impact on sectoral CO 2 emissions across all quantiles except some lower, middle, and higher quantiles. The study adds scientific value to existing knowledge by analyzing for the first time which EG sources are effective in reducing daily CO 2 emissions in the Global South. Based on the outcomes, the study demonstrates that WEG is the best EG source for Brazil, that SEG and WEG are optimal EG sources for India, and that China cannot benefit from the EG sources considered. In this way, the study provides fresh insights for the countries of the Global South and underlines the crucial role of renewable EG in ensuring carbon neutrality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Water evaporation-induced electricity generators (WEGs) have drawn widespread attention in the field of hydrovoltaic technology, which can convert atmospheric thermal energy into sustainable electric power. However, it is restricted in the wide application of WEGs due to the low power output, complex fabrication process, and high cost. Herein, we present a simple and effective approach to fabricate TiO 2 -carbon black film-based WEGs (TC-WEGs). A single TC-WEG device can sustainably output an open-circuit voltage of 1.9 V and a maximum power density of 40.9 μW/cm 2 . Moreover, it has been shown that TC-WEGs exhibit stable electrical energy output when operating in seawater, which can yield a short-circuit current of 1.2 μA. The superior electricity generation performance can be attributed to the intrinsic characteristics of the TC-WEGs, including hydrophilicity, porous structure, and electrical conductivity. This work provides an important reference for the constant harvesting of clean energy.

Methylene blue (MB) was regarded as a highly toxic and hazardous substance owing to its irreparable hazard and deplorable damage on the ecosystem and the human body. The treatment of this colorant wastewater appeared to be one of the towering challenges in wastewater treatment. In this study, a microbial fuel cell coupled with constructed wetland (CW-MFC) with effective MB elimination and its energy recuperation concurrently based on the incorporation of carbide lime as a substrate in a new copper oxide-loaded on carbon cloth (CuO/CC) cathode system was studied. The crucial influencing parameters were also delved, and the MB degradation and chemical oxygen demand (COD) removal efficiencies were correspondingly incremented by 97.3% and 89.1% with maximum power output up to 74.1 mW m -2 at optimal conditions (0.2 g L -1 carbide lime loading and 500 Ω external resistance). The carbide lime with high calcium ion content was greatly conducive for the enrichment of critical microorganism and metabolic activities. The relative abundances of functional bacteria including Proteobacteria and Actinobacteriota were vividly increased. Moreover, the impressive results obtained in printed ink wastewater treatment with a COD removal efficiency of 81.3% and a maximum power density of 58.2 mW m -2 , which showcased the potential application of CW-MFC., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study analyses the factors driving CO 2 emissions from electricity generation in Ghana from 1990 to 2020. Employing Logarithmic Mean Divisia Index (LMDI) and Autoregressive Distributed Lag (ARDL) techniques, the research decomposes electricity generation into different factors and assesses their impact on CO 2 emissions, considering both short and long-run effects. The LMDI analysis reveals that the total CO 2 emissions from electricity generation amount to 3.33%, with all factors contributing positively in each subperiod. Notably, fossil fuel intensity, production, and transformation factors exhibit substantial contributions of about 1.16%, 0.49%, and 0.48%, respectively. Contrastingly, the ARDL results highlight that only electricity intensity and production factors significantly increase CO 2 emissions by about 0.20% and 0.09% (0.38% and 0.10%) in the short-run (long-run), while other factors contribute to a reduction in electricity generation emissions. Overall, we conclude that electricity intensity and production factors are the primary drivers of CO 2 emissions from electricity generation in Ghana. Nevertheless, effective measures to address all decomposition factors is crucial for effective mitigation of electricity generation CO 2 emissions., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

The studies have focused on changes in CO 2 emissions over different periods, including the COVID-19 pandemic. Even if CO 2 emissions are temporarily reduced during the pandemic according to annual figures, this may be misleading. Considering annual figures is important to understand the overall trend, but using data with much higher frequency (e.g., daily) is much better suited to investigate dynamic relationships and external effects. Therefore, this study comprehensively analyzes the association between CO 2 emissions and disaggregated electricity generation (EG) sources across the globe by employing the novel wavelet local multiple correlation (WLMC) approach on daily data from 1st January 2020 to 31st March 2023. The results demonstrate that (1) based on the main statistics, daily CO 2 emissions range between 69 MtCO 2 and 116 MtCO 2 , indicating that there is an oscillation, but no sharp changes over the analyzed period. (2) based on the baseline regression using the dynamic ordinary least squares (DOLS) approach, the constructed estimation models have a high predictive ability of CO 2 emissions, reaching ~ 94%; (3) in the further analysis employing the WLMC approach, there are significant externalities between EG resources, which affect CO 2 emissions. The results present novel insights about time- and frequency-varying effects as well as a disaggregated analysis of the effect of EG on CO 2 emissions, demonstrating the significance of the energy transition towards clean sources around the world., (© 2024. The Author(s).)

Cr(VI) and p-chlorophenol (4-CP) are common pollutants in the aquatic environment but are difficult to degrade and have complex toxic effects. A downflow Leersia hexandra microbial fuel cell (DLCW-MFC) system was constructed to purify Cr(VI) and 4-CP polluted wastewater, as well as to investigate the effects of different pHs on Cr(VI) and 4-CP removal, electrochemical performance, physiological and biochemical responses, and Cr enrichment status of L . hexandra . The results showed that the DLCW-MFC had the highest Cr(VI) and 4-CP removal rates at pH 6.5, which were 99.0% and 78.6%, respectively. At the same time, 543 mV output voltage and 72.25 mW/m 2 power density of the system were generated at pH 6.5, which were better than those at pH 7.4 and pH 5.8. The electrochemical performance result showed that pH 6.5 enhanced charge transfer ability and ion diffusion ability of the system. pH 6.5 also promoted growth and photosynthesis, and enhanced the Cr enrichment capacity (4.56 mg/10 plants) of L. hexandra . These results demonstrate that pH 6.5 was the optimum pH for the DLCW-MFC synchronous treatment of Cr(VI) and 4-CP as well as the generation of electricity. The DLCW-MFC designed in this study will provide a reference for purifying polluted wastewater and generating electricity.

The growing global concern over the high phosphorus concentration in discharged wastewaters has driven the demand for exploring the means to recover it from wastewater. We previously demonstrated the possibility of phosphorus recovery by iron-air fuel cells from digested effluent. The present study focused on further optimizing the performance of the fuel cell by adjusting the wastewater properties (initial pH) and device parameters (anode/cathode area ratio, electrode spacing). Under neutral or slightly alkaline conditions, the HCO 3 ions accelerated the formation of iron anode passivation layer, resulting in a decreased phosphate removal efficiency and vivianite yield. Additionally, the occurrence of oxygen crossover with small electrode spacing and anode/cathode area ratio significantly influenced the efficiency of fuel cells in terms of phosphate removal, vivianite production, and electricity generation. The results showed that an acidic pH (5.78), an adequate anode/cathode area ratio (1.3), and an appropriate electrode spacing (5 cm) were prone to increase vivianite yield. Furthermore, the fuel cell achieved the highest electric energy output with an initial pH of 5.78, an anode/cathode area ratio of 0.4, and an electrode spacing of 7.5 cm. As far as operational cost was concerned, the iron-air fuel cell system exhibited a potential cost-saving advantage of about 65.6% compared to the traditional electrochemical crystallization system.- ions accelerated the formation of iron anode passivation layer, resulting in a decreased phosphate removal efficiency and vivianite yield. Additionally, the occurrence of oxygen crossover with small electrode spacing and anode/cathode area ratio significantly influenced the efficiency of fuel cells in terms of phosphate removal, vivianite production, and electricity generation. The results showed that an acidic pH (5.78), an adequate anode/cathode area ratio (1.3), and an appropriate electrode spacing (5 cm) were prone to increase vivianite yield. Furthermore, the fuel cell achieved the highest electric energy output with an initial pH of 5.78, an anode/cathode area ratio of 0.4, and an electrode spacing of 7.5 cm. As far as operational cost was concerned, the iron-air fuel cell system exhibited a potential cost-saving advantage of about 65.6% compared to the traditional electrochemical crystallization system., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Amidst the swift progression of microelectronics and Internet of Things technology, wearable devices are gradually gaining ground in the domains of human health monitoring. Recently, human bioenergy harvesting has emerged as a plausible alternative to batteries. This paper delves into harvesting human inertial energy that stimulates inertial masses through human motion and then transmutes the motion of the inertial masses into electrical energy. The inertial energy harvester is better suited for low-frequency and irregular human motion. This review first identifies the sources of human motion excitation that are compatible with inertial energy harvesters and then provides a summary of the operating principles and the comparisons of the commonly used energy conversion mechanisms, including electromagnetic, piezoelectric, and triboelectric transducers. The review thoroughly summarizes the latest advancements in human inertial energy-harvesting technology that are categorized and grouped based on their excitation sources and mechanical modulation methods. In addition, the review outlines the applications of inertial energy harvesters in powering wearable devices, medical health monitoring, and as mobile power sources. Finally, the challenges faced by inertial energy-harvesting technologies are discussed, and the review provides a perspective on the potential developments in the field., (© 2023 Wiley-VCH GmbH.)

An electrical application of green synthesized silver nanoparticles (Ag NPs) by developing a unique bio-electrochemical cell (BEC) has been addressed in the report. Here, garlic extract (GE) has been used as a reducing agent to synthesize Ag NPs, and as a bio-electrolyte solution of BEC. Ag NPs successfully formed into face-centered cubic structures with average crystallite and particle sizes of 8.49 nm and 20.85 nm, respectively, according to characterization techniques such as the UV-vis spectrophotometer, XRD, FTIR, and FESEM. A broad absorption peak at 410 nm in the UV-visible spectra indicated that GE played a vital role as a reducing agent in the transformation of Ag + ions to Ag NPs. After that four types of BEC were developed by varying the concentration of GE, CuSO 4 . 5H 2 O, and Ag NPs electrolyte solution. The open circuit voltage and short circuit current of all cells were examined with the time duration. Moreover, different external loads (1 Ω, 2 Ω, 5 Ω, and 6 Ω) were used to investigate the load voltage and load current of BEC. The results demonstrated that the use of Ag NPs on BEC played a significant role in increasing the electrical performance of BEC. The use of GE-mediated Ag NPs integrated the power, capacity, voltage efficiency, and energy efficiency of BEC by decreasing the internal resistance and voltage regulation. These noteworthy results can take a frontier forward to the development of nanotechnology for renewable and low-cost power production applications., (© 2023 IOP Publishing Ltd.)

The process industries play a significant role in boosting the economy of any nation. However, poor management in several industries has been posing worrisome threats to an environment that was previously immaculate. As a result, the untreated waste and wastewater discarded by many industries contain abundant organic matter and other toxic chemicals. It is more likely that they disrupt the proper functioning of the water bodies by perturbing the sustenance of many species of flora and fauna occupying the different trophic levels. The simultaneous threats to human health and the environment, as well as the global energy problem, have encouraged a number of nations to work on the development of renewable energy sources. Hence, bioelectrochemical systems (BESs) have attracted the attention of several stakeholders throughout the world on many counts. The bioelectricity generated from BESs has been recognized as a clean fuel. Besides, this technology has advantages such as the direct conversion of substrate to electricity, and efficient operation at ambient and even low temperatures. An overview of the BESs, its important operating parameters, bioremediation of industrial waste and wastewaters, biodegradation kinetics, and artificial neural network (ANN) modeling to describe substrate removal/elimination and energy production of the BESs are discussed. When considering the potential for use in the industrial sector, certain technical issues of BES design and the principal microorganisms/biocatalysts involved in the degradation of waste are also highlighted in this review., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in the paper., (Copyright © 2023. Published by Elsevier Ltd.)

Photosynthetic microbial fuel cell (PMFC) is a novel technology, which employs organic pollutants and organisms to produce electrons and biomass and capture CO 2 by bio-reactions. In this study, a new PMFC was developed based on Synechococcus sp. as a biocathode, and dairy wastewater was used in the anode chamber. Different experiments including batch feed mode, semi-continuous feed mode, Synechococcus feedstock to the anode chamber, Synechococcus-Chlorella mixed system, the feedstock of treated wastewater to the cathode chamber, and use of extra nutrients in the anodic chamber were performed to investigate the behavior of the PMFC system. The results indicated that the PMFC with a semi-continuous feed mode is more effective than a batch mode for electricity generation and pollutant removal. Herein, maximum power density, chemical oxygen demand removal, and Coulombic efficiency were 6.95 mW/m 2 (450 Ω internal resistance), 62.94, and 43.16%, respectively, through mixing Synechococcus sp. and Chlorella algae in the batch-fed mode. The maximum nitrate and orthophosphate removal rates were 98.83 and 68.5%, respectively, wherein treated wastewater in the anode was added to the cathode. No significant difference in Synechococcus growth rate was found between the cathodic chamber of PMFC and the control cultivation cell. The heating value of the biocathode biomass at maximum Synechococcus growth rate (adding glucose into the anode chamber) was 0.2235 MJ/Kg, indicating the cell's high ability for carbon dioxide recovery. This study investigated not only simultaneous bioelectricity production and dairy wastewater in a new PMFC using Synechococcus sp. but also studied several operational parameters and presented useful information about their effect on PMFC performance., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The electrochemical performances and denitrification efficiency of microbial fuel cells (MFCs) are often limited by chemical oxygen demand/nitrogen (COD/N) of wastewater. To overcome this limitation, single-chamber air cathode MFCs with varying COD/N (16/1, 8/1, and 4/1) were established to investigate their electrochemical performances, denitrification efficiency, and bacterial communities. The optimal COD/N for maximizing electricity generation and denitrification efficiency was 8/1, as supported by the greatest corrected coulomb efficiency (13.6%) and electron transfer rate (2.36 C/h for electricity generation, 39.77 C/h for denitrification). As COD/N decreased, the electrochemically active genus Geobacter was replaced by the denitrifying genera Un._f_Burkholderiaceae, Dechlorosoma, and Petrimonas. These results indicated that the efficiency of electricity generation and denitrification was not solely determined by the abundance of electrochemically active and denitrifying bacteria. The presence of a faster electron transfer pathway, possibly direct interspecies electron transfer, enhanced simultaneous electricity generation and denitrification in MFCs with COD/N of 8/1., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Environmental pollution and energy crisis have recently become one of the major global concerns. Insincere discharge of massive amount of organic and inorganic wastes into the aqueous bodies causes serious impact on our environment. However, these organic substances are significant sources of carbon and energy that could be sustainably utilized rather than being discarded. Photocatalytic fuel cell (PFC) is a smart and novel energy conversion device that has the ability to achieve dual benefits: degrading the organic contaminants and simultaneously generating electricity, thereby helping in environmental remediation. This article presents a detailed study of the recent advancements in the development of PFC systems and focuses on the fundamental working principles of PFCs. The degradation of various common organic and inorganic contaminants including dyes and antibiotics with simultaneous power generation and hydrogen evolution has been outlined. The impact of various operational factors on the PFC activity has also been briefly discussed. Moreover, it provides an overview of the design guidelines of the different PFC systems that has been developed recently. It also includes a mention of the materials employed for the construction of the photo electrodes and highlights the major limitations and relevant research scopes that are anticipated to be of interest in the days to come. The review is intended to serve as a handy resource for researchers and budding scientists opting to work in this area of PFC devices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Methyl Orange, an azo dye, is a widely used colouring agent in the textile industry. The study aimed to investigate the efficiency of bioremediating bacteria in degrading methyl orange. Escherichia coli (E. coli), a Methyl Orange-degrading bacterium, was isolated from cow dung and its biochemical properties were analysed using 16S rRNA sequencing, and MALDI-TOF MS. A pre-cultured strain of Pseudomonas aeruginosa was co-cultured with E. coli in 1:1 ration in a microbial fuel cell (MFC) for simultaneous electricity production and methyl orange degradation. The degradation was combined with biological wastewater treatment at varying Methyl Orange concentrations, and the electrochemical characteristics were analysed through polarisation study, cyclic voltammetry, and electrochemical impedance spectroscopy. The impact of parameters such as anolyte pH, dye concentration, incubation time, and substrate concentrations were also studied. This study confirmed E. coli as an effective methyl orange degrading bacteria with a maximum % degradation efficiency of 98% after 48 h incubation at pH 7.0. The co-culture of isolated microorganisms at 250 mg/L of methyl orange concentration showed a maximum power density 6.5 W/m 3 . Further, anode modification with Fe 2 O 3 nanoparticles on the anode surface enhanced power production to 11.2 W/m 3 , an increase of 4.7 W/m 3 ., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The emerging technology of harvesting environmental energy using hydrovoltaic devices enriches the conversion forms of renewable energy. It provides more concepts for power supply in micro/nano systems, and hydrovoltaic technology with high performance, usability, and integration is essential for achieving sustainable green energy. Comparing the discovery of multiscale nanomaterials, working layers with innovative microstructures have gradually become the dominant trend in the construction of graphene-based hydrovoltaic devices. However, reports on promoting ion/electron redistribution at the solid-liquid interface through the substrate effect of graphene are accompanied by tedious procedures, nondiverse substrates, and monolithic regulation of enhancement mechanisms. Here, the electrophoretic deposition (EPD)-driven SiC whiskers (SiC w )-assisted graphene transfer process is adopted to alleviate the complexity of the device fabrication caused by graphene transfer. The resulting output performance of the graphene/SiC w (GS) mesh films is significantly boosted. The high integrity of graphene and prominent negative surface charge near the graphene-droplet interface are derived from the overlayer and underlayer inside the graphene-based mixed-dimensional van der Waals (vdW) heterostructures, respectively. Additionally, a self-powered desalination-monitoring system is designed based on integrated hydrovoltaic devices. Electricity harvested from the ionic solutions is reused for deionization, representing an efficient strategy for energy conversion and utilization.

Swine wastewater, characterized by high organic and nutrient content, poses significant environmental challenges. This study aims to compare the effectiveness of two treatment technologies, namely Vertical Flow Constructed Wetland-Microbial Fuel Cell (VFCW-MFC) and Vertical Flow Constructed Wetland (VFCW), in terms of pollutant removal, electricity generation, and microorganism community dynamics. The results showed that the average removal efficiencies of chemical oxygen demand (COD), ammonia nitrogen, total nitrogen (TN), total phosphorus (TP) and sulfadiazine antibiotics (SDZ) by VFCW-MFC were as high as 94.15%, 95.01%, 42.24%, 97.16% and 82.88%, respectively, which were all higher than that by VFCW. Both VFCW-MFC and VFCW have good tolerance to SDZ. In addition, VFCW-MFC has excellent electrical performance, with output voltage, power density, coulombic efficiency and net energy recovery up to 443.59 mV, 51.2 mW/m 3 , 52.91% and 2.04 W/(g·s), respectively, during stable operation. Moreover, the microbial community diversity of VFCW-MFC was more abundant, and the species abundance distribution in cathode region was more rich and even than in anode region. At phylum level, the dominant microorganisms in VFCW-MFC included Proteobacteria, Bacteroidota, Firmicutes and Actinobacteriota, which showed good degradation effect on SDZ. Proteobacteria and Firmicutes are also involved in electricity production. Chloroflexi, Proteobacteria and Bacteroidota play a major role in nitrogen reduction., Competing Interests: Declaration of competing interest All of the authors declare that they have no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Constructed wetlands (CWs) have proven to be effective and environmentally friendly for removing pollutants, while microbial fuel cells (MFCs) offer the potential for electricity generation. Thus, this study evaluated the performance of three CW-MFC systems (zigzag, single-column, and triple-column continuous) for domestic wastewater treatment and electricity generation. Results showed that parallel connection of CW-MFCs significantly improved power generation compared to series connection. Additionally, using three copper wires to connect carbon fiber felt electrodes demonstrated superior pollutant capture capabilities compared to a single copper wire. During the 14-day testing period, the single-column system achieved the highest power density of 5.55 mW m -2 , followed closely by the triple-column continuous system at 4.77 mW m -2 . In contrast, the zigzag system exhibited a lower power density of 2.49 mW m -2 . Interestingly, the implementation of facultative anaerobic conditions in the anode, along with the application of a plastic bag cover, facilitated the maintenance of anaerobic conditions in both the single-column and triple-column continuous systems. This resulted in increased power density and reduced internal resistance. In contrast, the zigzag system, with its larger surface area, aeration, and circulation, exhibited higher internal resistance and lower current dissipation. Despite its inferior electricity generation performance, the zigzag system demonstrated higher efficiency removal of chemical oxygen demand (COD), nitrate (NO 3 - ), and phosphate (PO 4 3- ) than the single-column system. This can be attributed to the extended contact time, resulting in enhanced pollutant removal. Overall, the multi-column continuous system shows promise as a viable approach for simultaneous domestic wastewater treatment and electricity production, offering potential benefits for sustainable wastewater management., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Hydrovoltaic electricity generation (HEG) utilizes the latent environmental heat stored in water, and subsequently harvests the electrical energy. However, sustainable HEG has remained extremely challenging due either to complex fabrication and high cost, or to restricted environmental compatibility and renewability. Electroactive microorganisms are environmentally abundant and viable in performing directional electron transport to produce currents. These distinctive features have inspired microbial HEG systems that can convert environmental energy into hygroelectricity upon water circulation from raindrops, waves, and water moisture, and has recently succeeded as proof of concept for becoming a cutting-edge biotechnology. In this review, recent advances in microbial biofilm-based hydrovoltaic technology are highlighted to better understand a promising method of electricity generation from environmental energy with the aim of practical applications., Competing Interests: Declaration of interests No interests are declared., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The shortage of fossil fuels and freshwater resources has become a serious global issue. Using solar energy to extract clean water with a photothermal conversion technology is a green and sustainable desalination method. Integrated electricity generation during the desalination process maximizes energy utilization efficiency. Herein, a solar-driven steam and electricity generation (SSEG) system based on an all-in-one evaporator is prepared via a scalable technology. Carbon black is selected as the absorber for solar energy harvesting as well as the functional substance for simultaneous electricity generation. Fabric substrate with flexible structure, porous channel, and capillary effect is vital for directional brine supply, multiple solar absorption, and thermal management. The high evaporation rate (1.87 kg m -2  h -1 ) and voltage output (324 mV) can be achieved with an all-in-one device. The stable electricity output can be maintained over 40000 s. The SSEG performance remains constant after 15 operation cycles or 20 wash cycles. The integrated device balances excellent effectiveness and practicality, providing a viable path for clean desalination and electricity generation., (© 2023 Wiley-VCH GmbH.)

A wastewater treatment system has been established based on sulfate-reducing and sulfide-oxidizing processes for treating organic wastewater containing high sulfate/sulfide. The influence of COD/SO 4 ratio and hydraulic retention time (HRT) on removal efficiencies of sulfate, COD, sulfide and electricity generation was investigated. The continuous operation of the treatment system was carried out for 63 days with the optimum COD/SO 2- ratio and hydraulic retention time (HRT) on removal efficiencies of sulfate, COD, sulfide and electricity generation was investigated. The continuous operation of the treatment system was carried out for 63 days with the optimum COD/SO 4 was obtained with a sulfide removal efficiency of 93.0 ± 1.2%. However, the sulfide removal efficiency and power density decreased gradually after 45 days. The results from scanning electron microscopy (SEM) with an energy dispersive X-ray (EDX) show that sulfur accumulated on the anode, which could explain the decline in sulfide oxidation and electricity generation. This study provides a promising treatment system to scale up for its actual applications in this type of wastewater.2- ratio and HRT. The result showed that the COD and sulfate removal efficiencies were stable, reaching 94.8 ± 0.6 and 93.0 ± 1.3% during the operation. A power density level of 18.0 ± 1.6 mW/m 2 was obtained with a sulfide removal efficiency of 93.0 ± 1.2%. However, the sulfide removal efficiency and power density decreased gradually after 45 days. The results from scanning electron microscopy (SEM) with an energy dispersive X-ray (EDX) show that sulfur accumulated on the anode, which could explain the decline in sulfide oxidation and electricity generation. This study provides a promising treatment system to scale up for its actual applications in this type of wastewater.

In recent years, excessive exploitation and rapid population growth have posed numerous challenges. The climate crisis is deepening because of the unabated use of fossil fuels and the ascendance of greenhouse gas levels, so there is still an urgent need to seek different clean energy sources and electricity generating methods with the purpose of adjusting energy structures and solving environmental problems. In the ubiquitous hydrologic cycle, at least 60 petawatts (10 15 W) energy can be supplied, but little of it has yet been utilized. Nowadays, hydrovoltaic intelligence has emerged and exhibited an ecofriendly concept of electricity generation compared with traditional methods with the rise of nanoscience and nanomaterials. Hence, it provides the prospect of upgrading the mode of water energy use, constructing a renewable energy industry, and alleviating environmental issues. In this review, starting by introducing different types of hydrovoltaic effect mechanisms─energy harvesting based on drawing potential of liquids; energy harvesting based on water evaporation, and energy harvesting based on moisture adsorption─we summarize the fabrication processes, material classifications, intelligent applications, and representative advances in detail. Moreover, the future development trends of hydrovoltaic intelligence and the challenges for improvement in electrical output are further discussed.

Methane has been demonstrated to be a feasible substrate for electricity generation in microbial fuel cells (MFCs) and denitrifying anaerobic methane oxidation (DAMO). However, these two processes were evaluated separately in previous studies and it has remained unknown whether methane is able to simultaneously drive these processes. Here we investigated the co-occurrence and performance of these two processes in the anodic chamber of MFCs. The results showed that methane successfully fueled both electrogenesis and denitrification. Importantly, the maximum nitrate removal rate was significantly enhanced from (1.4 ± 0.8) to (18.4 ± 1.2) mg N/(L·day) by an electrogenic process. In the presence of DAMO, the MFCs achieved a maximum voltage of 610 mV and a maximum power density of 143 ± 12 mW/m 2 . Electrochemical analyses demonstrated that some redox substances (e.g. riboflavin) were likely involved in electrogenesis and also in the denitrification process. High-throughput sequencing indicated that the methanogen Methanobacterium, a close relative of Methanobacterium espanolae, catalyzed methane oxidation and cooperated with both exoelectrogens and denitrifiers (e.g., Azoarcus). This work provides an effective strategy for improving DAMO in methane-powered MFCs, and suggests that methanogens and denitrifiers may jointly be able to provide an alternative to archaeal DAMO for methane-dependent denitrification., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

The power performance of the bio-electrochemical fuel cells (BEFCs) depends mainly on the energy harvesting ability of the anode material. The anode materials with low bandgap energy and high electrochemical stability are highly desirable in the BEFCs. To address this issue, a novel anode is designed using indium tin oxide (ITO) modified by chromium oxide quantum dots (CQDs). The CQDs were synthesized using facile and advanced pulsed laser ablation in liquid (PLAL) technique. The combination of ITO and CQDs improved the optical properties of the photoanode by exhibiting a broad range of absorption in the visible to UV region. A systematic study has been performed to optimize the amount of CQDs and green Algae (Alg) film grown using the drop casting method. Chlorophyll (a, b, and total) content of algal cultures (with different concentrations) were optimized to investigate the power generation performance of each cell. The BEFC cell (ITO/Alg10/Cr3//Carbon) with optimized amounts of Alg and CQDs demonstrated enhanced photocurrent generation of 120 mA cm -2 at a photo-generated potential of 24.6 V m -2 . The same device exhibited a maximum power density of 7 W m -2 under continuous light illumination. The device also maintained 98% of its initial performance after 30 repeated cycles of light on-off measurements., (© 2023 Wiley Periodicals LLC.)

In order to develop efficient photoanode to improve the performance of visible light responsive photocatalytic fuel cell (PFC), in this work, polyaniline/g-C 3 N 4 /Bi 2 O 3 /Ti photoanode was successfully prepared using silica-sol drop coating method, and assembled with Cu cathode to construct PFC to decompose rhodamine B and generate electricity simultaneously. The degradation rate, maximum photocurrent density and maximum power density of this PFC were 91.23%, 0.086 mA cm -2 and 4.78 μW cm -2 , respectively, which were 1.4 and 1.8 times, 2.4 and 4.5 times, and 1.9 and 7.3 times those of the corresponding values of the PFCs with g-C 3 N 4 /Bi 2 O 3 /Ti and Bi 2 O 3 /Ti photoanodes, respectively. This is attributed to the type II heterojunction structure formed among polyaniline, g-C 3 N 4 and Bi 2 O 3 in the polyaniline/g-C 3 N 4 /Bi 2 O 3 /Ti photoanode. Among them, polyaniline has π-π conjugated structure, which can rapidly transfer the electronic charge between g-C 3 N 4 and Bi 2 O 3 , thus enhancing the separation efficiency of photo-generated e - -h + pairs spatially and reducing their recombination, extending the visible light response wavelength of the photocatalyst, and finally improving its photocatalytic properties. This study can provide significant reference for the research of Bi 2 O 3 -based visible light responsive PFC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Data was collected using standard communication equipment and invoices provided by an established civil construction and renewable energy development and operation company. Data referring to the construction, costings, operation and environmental impacts of a photovoltaic farm were recorded into four distinct Excel files namely: i) Project Management Data, ii) Life Cycle Inventory (LCI), iii) Electricity Generation Data and iv) Operational Cost Data. For the project management, the given quantities of the resources used in each activity could be further combined with the costs from different geographical and time regions to estimate overall project implementation costs for similar projects. The LCI data for the materials and transportation used can set the basis for life cycle assessment modelling of ground-mounted photovoltaic farms of that size and type. The electricity generation data along with meteorological parameters and location coordinates can be further enhanced to predict and manage energy generation and cashflow of expectations installations of this type and size over time. Finally, the data referring to a number of cost categories('maintenance costs', 'operational costs', 'insurance costs' and 'any other costs'), especially combined with the previously mentioned types of data could support a holistic technoeconomic and environmental assessment of comparable commercial photovoltaic installations. In addition, these data can be used for a comparative multi-disciplinary evaluation between photovoltaics and among various renewable electricity generation alternatives and traditional fossil fuel-based options as well., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors declare no conflict of interest except the co-author – Anastasia Pavlidou who is the President and CEO of the company engaged as the Principal Contractor and acted as the contractor's representative for each project., (© 2023 The Author(s).)

Utilizing biogas as a fuel for heating and power generation usually requires desulfurization pretreatment. In this study, the biogas utilization without desulfurization pretreatment in a bioelectrochemical system (BES) was explored. The results showed that the biogas-fueled BES was successfully started up within 36 d and the presence of hydrogen sulfide promoted both methane consumption and electricity generation. The optimal performance (i.e., a methane consumption of 0.523 ± 0.004 mmol/d, a peak voltage of 577 ± 1 mV, a coulomb production of 37.86 ± 0.43C/d, a coulombic efficiency of 9.37 ± 0.06 % and the maximum power density of 2.070 W/m 3 ) was obtained under bicarbonate buffer solution and 40 °C conditions. The addition of 1 mg/L sulfide and 5 mg/L L-cysteine facilitated methane consumption and electricity generation. In the anode biofilm, the dominant bacteria were Sulfurivermis, unclassified_o__Ignavibacteriales and Lentimicrobium, while Methanobacterium, Methanosarcina and Methanothrix were the predominant archaea. Besides, the metagenomics profiles reveal that anaerobic methane oxidation and electricity generation were closely related to sulfur metabolism. These findings provide a novel approach for utilizing biogas without desulfurization pretreatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The traditional technologies for industrial and agricultural effluent treatment are often energy-intensive. Herein, we suggest an electrochemical redox strategy for spontaneous and simultaneous decontamination of wastewater and generation of both fuels and electricity at low cost. Using hydrazine and nitrate effluents as a demonstration, we propose a hydrazine-nitrate flow battery (HNFB) that can efficiently purify the wastewater and meanwhile generate both ammonia fuel and electricity with the assistance of our developed bimetallic RuCo precatalyst. Specifically, the battery delivers a peak power density of 12 mW cm -2 and continuously operates for 20 h with an ammonia yield rate of ca. 0.38 mmol h -1  cm -2 under 100 mA cm -2 . The generated electricity can further drive a hydrazine electrolyzer to produce hydrogen fuel. Our work provides an alternative pathway to purify wastewater and generate high value-added fuels at low cost., (© 2023 Wiley-VCH GmbH.)

In this work, a photocatalytic fuel cell (PFC) with a gas diffusion TiO 2 photoanode is proposed to directly convert chemical energy contained in volatile organic compounds into electricity by using solar energy. The gas diffusion TiO 2 photoanode is prepared by coating TiO 2 nanoparticles onto Ti mesh, whose intrinsic porous structure allows for gaseous pollutants to directly transfer inside the photoanode and thereby enhances mass transport. The feasibility of the developed gas diffusion photoanode is demonstrated by degrading toluene as a model gaseous pollutant. It is shown that the newly-developed PFC yields better electricity generation and toluene removal efficiency due to the enhanced mass transport of toluene and the eliminated interference of gas bubbles. The short-circuit current density and maximum power density of the PFC with a gas diffusion TiO 2 photoanode (0.1 mA/cm 2 and 0.02 mW/cm 2 ) are about 3.3 times and 4 times as those of the bubbling PFC (0.03 mA/cm 2 and 0.005 mW/cm 2 ), respectively. Both the discharging performance and toluene removal efficiency increase with increasing the light intensity and electrolyte concentration, while there exists an optimal gas flow rate leading to the best performance. The present work provides an innovative strategy for clean processing of volatile organic compounds while recycling the contained chemical energy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Wastewater treatment is typically energy-intensive. To achieve carbon neutrality, new wastewater treatment technologies that have high efficiency and low energy consumption must be developed. In this study, a reverse electrodialysis (RED) cell-modified photocatalytic fuel cell (PRC) for efficient electricity and hydrogen generation from the degradation of refractory organic pollutants is developed and evaluated. A hydrogen evolution cathode was developed and optimized by doping 1.53 wt. % Ni-N-C on CoP/NF. The bias voltage generated from the RED stack accelerated the separation of photoinduced holes and electrons on the photoanode, which enhances ampicillin (AMP) degradation and hydrogen production. The RED stack and electrode reactions respectively contribute 72.3 % and 27.7 % to the electricity production of PRC. The output current and cumulative hydrogen generation reach 2.2-3.0 mA and 500 μmol/L respectively with 81.8 % AMP removal. Increasing high concentration (HC), flow rate of NH 4 HCO 3 solutions and AMP concentration could increase the electricity and hydrogen generation. Acidic environment is helpful to improve the reaction rate of hydrogen evolution. We believe this study would provide a promising option for wastewater remediation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)