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Nickel-containing electroplating sludge (NiES) and dyeing sludge (DS) were used to prepare oxygen carriers (OCs) for chemical looping gasification (CLG) of DS. X-ray diffraction (XRD), surface area and porosity analysis were employed to investigate the crystal structure and pore structure of NiES and DS ash OCs. It was found that OCs prepared at 850 ℃ for 8 h (850NiES8, 850DS8) exhibited good characteristics in terms of pore structure. X-ray fluorescence (XRF), hydrogen temperature programmed reduction (H

In the present study, Ru modified hierarchical zeolites xRu-MZSM were developed for cellulose fast pyrolysis. Comprehensive catalyst characterizations including XRD, XPS, N2 adsorption-desorption, Py-IR and so on, were performed to unveil the essential structural properties. The chemical modification and Ru decoration remarkably regulated the distribution of Bronsted/Lewis acid sites. The presence of RuOx species would supply abundant strong Lewis acid sites for participating catalytic cracking, dehydration, decarbonylation, decarboxylation, cyclization, aromatization, etc., in cooperation with Bronsted acid sites. In-situ generated active Ru0 centers during cellulose pyrolysis might facilitate the proceeding of deoxygenation, hydride transfer, and dehydrogenation. Among the as-prepared catalysts screened, 2Ru-MZSM was much more efficient in aromatics production from cellulose fast pyrolysis compared to parent ZSM, wherein the total aromatics yield achieved 16.8% at temperature of 650 °C and heating rate of 10 °C/ms with corresponding E value as low as 23.40 kJ/mol. Also, plausible reaction mechanism for xRu-MZSM involved cellulose fast pyrolysis was proposed in detail.

In the present research, a series of metal oxides were employed to investigate the role of varied acid-base site on kinetics and mechanism for catalytic fast pyrolysis of cellulose using TG-MS and Py-GC/MS. The results showed that the modulation of acidity-to-basicity value via altering metal oxides constituents significantly affected the transformation pathway for cellulose pyrolysis. Higher acidity-to-basicity ratios accelerated the proceeding of deoxygenation process, wherein 39.4% aromatics and 34.7% aliphatic hydrocarbons were achieved using Al2O3 (acidity-to-basicity value of 1.38) at 750 °C with a catalyst/cellulose mass ratio of 15:1. In comparison, lowering acidity-to-basicity ratios mainly facilitated the ketonization and aldol condensation, therefore over 70% ketones was attained in the case of CaO catalysis. The kinetic studies further verified the promotional role of acid-base sites on cellulose pyrolysis with apparent activation energy as low as 33.72 kJ/mol, in comparison with that of cellulose pyrolysis without adding catalysts. From another aspect, the composite metal oxides with better porous structures contributed to deoxygenation conversion for the production of aromatics and aliphatic hydrocarbons. Moreover, plausible reaction pathway for cellulose pyrolysis over metal oxides was proposed. This work would provide a good reference for the realization of product regulation from cellulose pyrolysis via adjusting acid-base sites in metal oxides.

e-Caprolactone is traditionally produced through Baeyer-Villiger oxidation of cyclohexanone oxidized by peracids in industry, which inevitably results in large discard acid and environmental pollution. To this end, a green route to e-caprolactone was developed by coupling the direct generation of hydrogen peroxide from aerobic oxidation of benzhydrol catalyzed by NHPI and Baeyer-Villiger oxidation of cyclohexanone with the in situ hydrogen peroxide over Sn-Beta zeolites in one pot. Molecular oxygen was employed as the terminal oxidant, and the effects of several reaction factors were studied. Compared with one-step process, the one-pot two-step method noticeably improved the selectivity of e-caprolactone. When the amount of in situ hydrogen peroxide was 0.72 equivalent, the selectivity of e-caprolactone was obtained 94.8% with 39.2% conversion of cyclohexanone, and the efficiency of H2O2 was up to 51.5%. As compared to the commercial 30 wt% aqueous H2O2 added directly, in situ H2O2 dramatically improved the selectivity of e-caprolactone and had higher efficiency. Additionally, the catalyst could be easily separated from the reaction solution and reused several times without the remarkable loss of activity.

This study developed an efficient and sustainable hydrometallurgical process for the enrichment of gold and silver and the stepwise separation of copper, zinc, and lead from sulfated roasted sand of waste printed circuit board smelting ash. Selective separation of copper and zinc was achieved by water leaching, and silver dispersion was reduced by controlling the amount of NaCl added during the leaching process. The results of the water leaching showed that the copper and zinc leaching rates were 99.85% and 99.47%, respectively, whereas the loss rate of silver was 2.1% with optimal leaching parameters. The high-chloride-complex method was used to study the efficient conversion and separation of lead from the leached residue, and the leaching kinetics and conversion mechanism of lead were discussed. The results showed that under the optimal conditions, the leaching rate of lead was 99.79%. Leaching kinetics analysis showed that lead leaching in the high - chlorine system was controlled by a chemical reaction; the apparent activation energy was 53.63 kJ/mol. After the leaching of copper, zinc, and lead, 1.66% Ag and 213 g/t Au were enriched in the leached residue; and the precious metal enrichment goal was reached. The chlorinated leachate showed good recycling performance, and a lead leaching rate of 97.93% was obtained after three circulations. After cooling, crystallization, and purification, lead chloride with a purity of 99.89% and high economic and industrial value was obtained from the lead-rich leachate. This process has favorable and sustainable industrial application prospects.

Waste rice husk char supported Fe and Ni were synthesized to prepare the monometallic and bimetallic catalysts for removing the tar model compound benzene in a laboratory dual-stage reactor. The prepared catalysts were examined by microstructure and textural characterization to analyse catalytic performance and stability. The molar proportions of CO, H2, CO2 and CH4 in the generated gas and the influence of residence time (τ) and the steam-to-carbon ratio (S/C) on the catalytic reaction were investigated. The results show that the rice husk char-based catalysts showed excellent catalytic activity for syngas production and benzene conversion. Under optimized conditions, the benzene conversion can reach 95.2%, and the mol% of syngas in the generated gas is greater than 93.0%, of which 91.0% is H2. The experimental results show that the influence of residence time on catalytic performance is greater than that of the steam-to-carbon ratio, and that excessive τ or S/C values will have no more positive effect on the performance of the catalyst. The stable active sites on the catalyst surface can guarantee the catalytic activity in the reaction. Ultimately, rice husk char-based catalysts can be used to remove tar and produce syngas.

Potassium is an inorganic mineral element in biomass and has a significant catalytic effect on biomass pyrolysis. In this work, the effect of potassium on the pyrolysis of biomass components (cellulose, xylan and lignin) was investigated with the help of thermogravimetric analyzer coupled to fourier transform infrared spectrometer (TG-FTIR) and pyrolysis-gas chromatography coupled to mass spectrometry (Py-GC/MS). The results showed that potassium accelerated the start of the main pyrolysis stage of the biomass components, reduced the weight loss rate for cellulose and lignin, and increased the weight loss rate for xylan. On the other hand, potassium presented a promotion effect on the formation of char for cellulose but a suppression effect for lignin. In addition, an increasing potassium content promoted the release of volatile products for xylan. Product distribution analysis found that potassium promoted the scission of glycosidic bonds and the decomposition of glucose units, resulting in a sharp yield decrease of carbohydrates and a yield increase of furans, aldehydes and ketones. In addition, an increased production of CO2 was obtained, indicating that potassium favors the cleavage and reforming of carboxyl (COOH) and carbonyl (CO) groups. Furthermore, the effect of potassium on the pyrolysis of cellulose and xylan was stronger than that on lignin pyrolysis. The effect on the pyrolysis reaction also resulted in a higher activation energy for the decomposition of biomass components, especially at high temperature intervals. Moreover, the higher the content of potassium added, the greater the increase was in the activation energy.

Data auditing enables data owners to verify the integrity of their sensitive data stored at an untrusted cloud without retrieving them. This feature has been widely adopted by commercial cloud storage. However, the existing approaches still have some drawbacks. On the one hand, the existing schemes have a defect of fair arbitration, i.e., existing auditing schemes lack an effective method to punish the malicious cloud service provider (CSP) and compensate users whose data integrity is destroyed. On the other hand, a CSP may store redundant and repetitive data. These redundant data inevitably increase management overhead and computational cost during the whole data life cycle. To address these challenges, we propose a blockchain-based public auditing and secure deduplication scheme with fair arbitration. By using a smart contract, our scheme supports automatic penalization of the malicious CSP and compensates users whose data integrity is damaged. Moreover, our scheme introduces a message-locked encryption algorithm and removes the random masking in data auditing. Compared with the existing schemes, our scheme can effectively reduce the computational cost of tag verification and data storage costs. We give a comprehensive analysis to demonstrate the correctness of the proposed scheme in terms of storage, batch auditing, and data consistency. Also, extensive experiments conducted on the platform of Ethereum blockchain demonstrate the efficiency and effectiveness of our scheme.

Pyrolytic char as a catalyst carrier has been widely used in tar removal. This paper aimed to develop a cost-effective and eco-friendly tar steam reforming approach by using waste peat char supported Ca catalysts in a laboratory dual-stage reactor. Tar model compound toluene was used in steam reforming experiment for facilitate fundamental research. The reaction temperature, residence time, steam-to-carbon ratio and the molar ratios of H2, CO, CO2 and CH4 in the generated gas were investigated. Experimental results show that the peat char supported Ca catalysts had good selectivity for H2, especially the catalyst which activated by KOH and CO2. The catalyst demonstrated better catalytic activity with a higher residence time (0.6 s–0.7 s) and S/C ratio (S/C > 2.5). Under the optimized conditions, the toluene conversion and the mol% of H2 can reached 94.4% and 68.5%, respectively. Meanwhile, the activity of the catalyst was proved by a variety of performance tests, and the deactivation and mechanism of catalysts were investigated. Finally, these cost-effective and green peat char-supported Ca catalysts could be used for tar removal.

This study is devoted to the scalable fabrication of a high-performance composite photocatalyst by incorporation of the visible-light-active CdS flowers (with sharp edges exposed) onto a TiO2 nanotube array (TNA) film on the Ti foil substrate. To evaluate the visible-light-harvesting performance of the prepared hierarchical architecture consisting of the CdS flowers, TNAs, and Ti foil, we subsequently assembled a photoelectrochemical (PEC) cell with membrane electrode assemblies fabricated innovatively by thermocompression. The CdS flowers can efficiently harvest the visible light energy, while TiO2 collects photoelectrons, effectively separating of the photoexcited electron-hole pairs and hence enhancing the photocatalysis efficiency in the photoelectrochemical conversion and yield of hydrogen production from water splitting. An impressive hydrogen production rate of 22.44 μmol▪h−1▪cm−2 was obtained in the PEC cell with the CdS flowers-sensitized TNA film under simulated solar light with an active irradiation area of around 42 cm2, thus showing great potential for practical applications.

In this study, a novel way to enhance the power-output performance of a Rhodococcus pyridinivorans (HR-1) –inoculated microbial fuel cell (MFC) with salinomycin was demonstrated. In the 5 mg/L salinomycin-treated MFC, the maximum power density and current density was promoted by 63.9 % and 28.1 % times, respectively. Cyclic-voltammetry (CV) analysis revealed that upon the addition of salinomycin the activity of electrochemical substances was enhanced, which resulted in the current-density promotion of the MFC. Salinomycin, as a cationic binding agent that can specifically bind to the channel protein, was responsible for electron transfer from the intracellular level to the micro-organism’s surface. Electrochemical impedance spectroscopy (EIS) results revealed that the internal resistance of the MFC was diminished after treatment with salinomycin, and thus it was speculated that the obstruction posed by the bio-membrane for electron transfer was reduced.

Converting peanut shells into biochar by pyrolysis was considered an environmentally friendly and efficient method for agricultural solid waste disposal. The properties of peanut shell-derived biochar (PBC) under different temperature and its adsorption capacity of heavy metals were investigated. It was found that PBC400 exhibited the highest cumulative capability for heavy metals elimination in single solute because of its high specific surface area and rich functional groups. Furthermore, the competitive adsorption revealed that PBC had a substantial difference in adsorption affinity from diverse heavy metal ions, sorption capacity decreased as Pb2+ > Cu2+ > Cd2+ > Ni2+ > Zn2+, which was lower than in a single solute. The adsorption process using selected biochar was optimized with respect to pH, reaction time, adsorbent dose, and initial concentration of heavy metals. The kinetic data was well fitted with PSO model, and the Langmuir model was adopted for adsorption equilibrium data in both cases of single solutes and mixed solutes for all heavy metals, which indicated that the removal course was primarily explained by monolayer adsorption, and chemical adsorption occupied an important role. Therefore, peanut shells derived biochar could be a potential and green adsorbent for wastewater treatment.

Lightweight and low filler loading of electromagnetic wave absorption materials remain a huge challenge under the premise of strong absorption and broad absorption band. Here, we offer a facile strategy to prepare the ultralight self-supported N-doped reduced graphene oxide aerogels containing pod-like N-doped carbon nanotubes and FeNi@N-doped graphene layer core-shell nanoparticles for high-performance electromagnetic wave absorbing materials. The mass density of the ultralight aerogels is 0.0131 g cm−3, greatly lower than those of activated carbons. With a filling loading of only 10 wt% and the matching thickness of 2.0 mm, the minimal reflection loss of aerogels reaches −39.39 dB at 13.28 GHz. When the matching thickness is smaller than 2.0 mm (1.6–2.0 mm), the minimal reflection loss values of the optimized aerogels can still exceed −20 dB superior to most of reported electromagnetic wave absorption counterparts. Moreover, its maximum effective absorption bandwidth is up to 4.7 GHz at the matching thickness of merely 1.8 mm. The excellent performance of the ultralight bimetal-based aerogels mainly derives from increased dielectric loss, better matching impedance and larger specific surface area. It could be believed our designed ultralight self-supported aerogels can be promising candidates for lightweight absorbers with strong attenuation abilities.

Three-dimensional (3D) graphene-based structures have attracted much attention due to their unique physicochemical properties and potential applications in various fields. In this work, we develop a facile strategy for growing Co and Zn-contained nitrogen-doped carbon nanotubes on the graphene sheets for the absorption of electromagnetic wave (EMW). The as-fabricated 3D structures with a larger surface area have high electrical conductivities, abundant defects, numerous interfaces and porous feature, endowing them to excellent EMW absorption performance. The minimal reflection loss and efficient absorption bandwidth of the optimized 3D structure can reach to −47.31 dB and 4.01 GHz at a low thickness of merely 1.5 mm, respectively. Even at the thickness of 1.2–1.5 mm, the minimal reflection losses are less than −10 dB. Furthermore, the filler mass loading of the 3D structures is only 6 wt%, lower than those of most of the reported absorbers. Our results highlight the importance of 3D structures composed of graphene and nitrogen-doped carbon nanotubes to high-efficiency EMW absorption.

Biomass tar was a conspicuous hazardous byproduct from biomass gasification, and it has become a great challenge in the development of biomass energy technology. Here, we proposed the facile one-step synthesis of highly porous carbon using biomass tar as feedstock, porous CaO as a template, and KOH as an activation agent. Following a simultaneous activation-template-carbonization process, the product displayed tunable porosity and high specific surface area (up to 2424 m2 g−1). When applied to CO2 capture, the ultramicropores of this carbon material played a significant role in enhancing the CO2 affinity. In particular, the adsorbent synthesized with biomass tar:CaO:KOH in 1:2:3 wt ratio exhibited the high CO2 capture capacity of 5.03 and 3.13 mmol g−1 at 273 K and 298 K (1.20 mmol g−1 at 0.15 bar), respectively, perfect cyclic regeneration property (95% retention) and excellent initial isosteric heat of adsorption (48.55 kJ mol−1). The CO2/N2 selectivity from Henry’s Law and ideal solution adsorption theory reached 26.3 and 15.4 at 273 K, and 32.4 and 19.7 at 298 K, respectively.

Macrophages have been recognized as a vital factor that can promote renal fibrosis. Previously we reported that the EGFR mimotope could alleviate the macrophage infiltration in the Sjögren's syndrome-like animal model. In current study, we sought to observe whether the active immunization induced by the EGFR mimotope could ameliorate renal fibrosis in the murine Unilateral Ureteral Obstruction (UUO) model. A series of experiments showed the EGFR mimotope immunization could ameliorate renal fibrosis, reduce the expressions of fibronectin, α-SMA and collagen I and alleviate the infiltrations of F4/80+ macrophages in UUO model. Meanwhile, the EGFR mimotope immunization could inhibit the EGFR downstream signaling. Additionally, the frequency of and F4/80+CD9+/FAS+ macrophages significantly increased in spleen after the EGFR mimotope immunization. These evidence suggested that the EGFR mimotope could alleviate renal fibrosis by both inhibiting EGFR signaling and promoting macrophages apoptosis.

The emergence of the Internet of Things (IoT) has been greatly applied for improving people’s lives. Through the combination with cloud computing resources, the IoT is no longer constrained by computing and storage resources. For the storage service of IoT/cloud, it is crucial to keep the data within some specific geolocation borders for improving storage service quality. At the same time, it can protect the security of data against natural or man-made disasters. However, the outsourcing model results in the data owners losing their physical control over their data, which makes it difficult for the data owners to check the geolocation of their outsourced data with the potentially semi-honest cloud service providers (CSPs). To provide a secure cloud data geolocation against semi-honest CSPs, we propose an efficient data geolocation scheme, and it can be applied into distributed cloud data geolocation. It combines both the proof of retrievability technique and the delay-based geolocation technique for cloud users, the purpose is to check both the retrievability and geolocation of their outsourced data stored in CSPs. By using a novel server-centric broadcast measurement, the scheme can provide more effective detection of the location forgery attacks from potentially semi-honest CSPs. Finally, the theoretical analysis and experimental evaluation show that the proposed scheme is secure and effective.

Modifying the surface of an anode can improve electron transfer, thus enhancing the performance of the associated bioelectrochemical system. In this study, a porous N-doped carbon cloth electrode was obtained via a simple thermal reduction and etching treatment, and then used as the anode in a bioelectrochemical system. The electrode has a high nitrogen-to‑carbon (N/C) ratio (~3.9%) and a large electrochemically active surface area (145.4 cm2, about 4.4 times higher than that of the original carbon cloth), which increases the bacterial attachment and provides more active sites for extracellular electron transfer. Electrochemical characterization reveals that the peak anodic current (0.71 mA) of the porous N-doped carbon cloth electrode in riboflavin is 18 times higher than that of the original carbon cloth electrode (0.04 mA), confirming the presence of more electroactive sites for the redox reaction. We also obtained a maximum current density of 0.29 mA/cm2 during operation of a bioelectrochemical system featuring the porous N-doped carbon cloth electrode, which is 14.5 times higher than that of the original carbon cloth electrode. This result demonstrates that the adoption of our new electrode is a viable strategy for boosting the performance of bioelectrochemical systems.

A series of TiO2/biochar composite catalysts were prepared by the hydrolysis method for the degradation of methyl orange, where biochar was obtained from the pyrolysis of waste walnut shells. The catalysts were examined by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL) and X-ray photoelectron spectroscopy (XPS), elemental analysis and ultra violet-visible diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity results showed that the catalysts noted as CT0.1/1, CT0.2/2 and CT 0.5/1 exhibited higher catalytic activity than that of pure TiO2. Besides, catalyst CT0.2/1 exhibited the highest catalytic activity (the decolorization efficiency of 96.88% and the mineralization efficiency of 83.23% were obtained), attributed to the synergistic effect of biochar and TiO2, while CT1/1 possessed the lowest activity due to the shelter of light by the excess biochar. After 5 repeated use, the catalyst CT0.2/1 still exhibited rather high activity toward the degradation of MO, where the decolorization efficiency and mineralization efficiency of MO achieved 92.45% and 76.56%, and the loss of activity was negligible.

Most of metal−organic frameworks (MOFs) themselves have low electrical conductivities, leading to bad electromagnetic wave (EMW) absorption properties. Herein we found that the EMW absorption property of zeolitic imidazolate frameworks-8 (ZIF-8) particles was improved unexpectedly after coupling them with graphene sheets. Experimental results and theoretical calculations indicated that well-defined interfaces between ZIF-8 and the graphene sheets were crucial to the improvement of EMW absorption property. Our strategy presented here may open a new way for designing other MOFs based hybrids for high-performance EMW absorbers.

Although oxygen reduction reaction (ORR) plays a key role in the cathodic part of many emerging energy conversion devices, it has naturally suffered from sluggish kinetics and high overpotential. We here report the facile synthesis of Fe-N co-doped carbon with a hierarchical porosity and in-situ formed graphene from biomass tar using urea as the nitrogen dopant, and FeCl3 as the porogen, catalyst, and Fe dopant. This exhibited an ORR catalytic activity comparable to that of a Pt/C catalyst in relation to its onset potential, limited diffusion current, and stability under an alkaline condition. It was found that the excellent catalytic performance should have originated from its large specific surface area, abundant active centers, and long-term conductive network. This renewable non-noble-metal catalyst may serve as an appropriate alternative to conventional noble catalysts in ORR-based techniques, and will also encourage investigations on the use of biomass tar for advanced materials toward various ends. Keywords: Biomass tar, Graphene, Hierarchically porous carbon, Co-doping, Oxygen reduction reaction

Biogas slurry is an environmental pollution source if it is discharged without proper treatment. In this work, a membrane system is designed to concentrate, and hence to recover the nutrient in the biogas slurry. The effects of pre-treatment technology, pH, temperature, operating pressure and module types of the reverse osmosis unit were studied via analyzing the chemical oxygen demand (COD), ammonia nitrogen, total nitrogen, conductivity in the permeate and retentate, and the volume concentration ratio. A dual stage reverse osmosis (RO) process is also applied to further enhance the performance, the concentration ratio reaches above 5 within 80 mins of operation, while the nutrient recovery and water recovery rates are 98% and 92.52%, respectively. The COD and ammonia nitrogen rejection rates are 99.41% and 99.11%, respectively; the quality of the permeate is in accordance with the national standard for water discharging.

In this study, the biochar which was obtained from peat was modified and served as the support for the preparation of cost-effective solid base catalysts for the transesterification reaction. The composition, structure and texture of prepared catalysts were examined by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), N2 adsorption/desorption, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and the Hammett indicator method. It was found that the surface area and pore volume of the peat biochar were increased significantly (from 80.25 m2/g and 105.36 mm3/g to 230.86 m2/g and 296.23 mm3/g, respectively) by chemical activation treatment with KOH. The best performance is observed for the resulting 30Ca/APB-700 catalyst (30% CaO loading and 700 °C calcination temperature), and over biodiesel yield of 93.4% was achieved at catalyst amount of 5 wt.%, methanol/oil molar ratio of 8:1 and reaction time of 150 min. Besides, after reused for 10 cycles, the catalytic efficiency had a slight deactivation in biodiesel production (above 81.6% of yield obtained). The high stability of catalyst was mainly attributed to the formation of Ca O Si bond on the catalyst surface.