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Electrochemical biomass oxidation coupled with hydrogen evolution offers a promising route to generate value‐added chemicals and clean energy. The complex adsorption behavior of 5‐hydroxymethyl furfural (HMF) and hydroxyl ions (OH−) on the electrocatalyst surface during HMF electrooxidation reaction (HMFOR) necessitates an in‐depth understanding of active sites available for adsorption. Herein, oxygen vacancy (VO) defects are introduced in NiFe layered double hydroxide (LDH) using Ce dopants to manipulate electronic structure. Synchrotron‐based HE‐XRD and XAS indicate negligible VO in La‐doped NiFe while Ce doping leads to VO defects due to flexible Ce redox (Ce3+↔ Ce4+). The VO‐rich Ce‐NiFe exhibits higher Faradic efficiency of ≈90% to produce 2,5‐furan dicarboxylic acid (FDCA), far greater than ≈60% for NiFe VO in Ce‐NiFe act as alternative active sites for OH− adsorption, hence reducing adsorption competition for the same metal sites. DFT calculation results corroborate experimental findings by showcasing that the presence of VO in Ce‐NiFe manipulates the adsorption energies and facilitates the chemical adsorption OH− in VO to improve HMFOR. In situ HE‐XRD derived pair distribution function coupled to RMC simulations confirm OH− trapping in VO and HMF adsorption on metal centers as evident by interlayer distance evolution. Taken together, this work showcases routes for dual‐site electrocatalyst design for improved biomass electrooxidation. [ABSTRACT FROM AUTHOR]

The co‐electroreduction of CO2 and NOx⁻ (NO3⁻/NO2⁻) to generate formamide (HCONH2) offers an opportunity for downstream chemical and polymer manufacturing decarbonization; however, significant challenges lie in the C‒N coupling and the associated low product selectivity. Herein, p‐block metal oxides are incorporated in copper oxides to provide more accessible active sites for reactant adsorption and activation, tuning the reaction selectivity toward the formamide production. Through in situ Raman and synchrotron‐based infrared spectroscopy measurements, C─N bond formation is demonstrated in real‐time with the CuOx/BiOx catalyst, where the C─N bond is detected via a *CHO and *NH2 intermediates formation, in agreement with the density functional theory calculations. When tested in a flow electrolyzer, a formamide yield rate of 134 ± 11 mmol h−1 gcat−1 is reported, the first report of co‐electroreduction of CO2 and NOx⁻ to formamide beyond conventional H‐cell measurements. These new insights on the C‒N coupling mechanisms and scale‐up capability provide directions for further development of electrocatalysts for the formamide production. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries hold promise as alternative systems to lithium‐based batteries. However, practical development faces critical challenges due to parasitic side reactions and dendrite growth in zinc anodes. While introducing electrolyte additives is promising, monofunctional additives offer limited protection to the zinc anode from a single aspect. Herein, a disodium succinate additive is presented to establish a hydrophobic and zincophilic dual electric layer structure on the Zn surface, regulate the solvation structure of Zn2+, and act as a pH buffer during cycling. As a result, the symmetrical cell with an electrolyte containing 0.2 m SADS shows a durable life of over 2200 h, and the Zn||MnO2 full cell still maintains an 80% capacity retention after 1000 cycles. In addition, SADS both show wide applicability in the match with NVO and I2 cathode. This work provides a low‐cost and multifunctional electrolyte additive, facilitating the development of high‐performance aqueous zinc ion batteries. [ABSTRACT FROM AUTHOR]

Simultaneously improving the electrochemical methanol oxidation reaction (MOR) and hydrogen evolution reaction (HER) using the electrolysis technique is a significant yet challenging task. To tackle this, we report a colloidal synthesis of Cr-dopant induced crystal orientation and shape modulation in Ni2P nanocrystals (NCs) as an advanced bifunctional electrocatalyst for electrosynthesis of value-added formate from the MOR at the anode and hydrogen at the cathode. We demonstrate that a two-electrode overall methanol splitting (OMeS) system using Cr-doped Ni2P nanorods (NRs) as a bifunctional catalyst can achieve a lowest voltage of 1.16 V to reach a current density of 10 mA cm−2, compared to the cell voltage of 1.65 V for overall water splitting. Combined experimental and theoretical investigations revealed that the Cr-dopant induces shape modulation and crystal orientation in Ni2P, which favors the thermodynamics of the dehydrogenation process in the MOR and hydrogen adsorption in the HER, leading to enhanced electrocatalytic activities. Interestingly, a proof-of-concept solar-driven system fabricated using a commercial Si photovoltaic cell integrated with an OMeS cell employing bifunctional Cr-doped Ni2P NRs generated a stable photocurrent density of ∼12.3 mA cm−2 for 60 min., demonstrating its promise for energy-efficient and selective electrosynthesis, enabling the production of valuable chemicals and clean hydrogen in a sustainable manner. [ABSTRACT FROM AUTHOR]

The practical application of aqueous zinc‐ion batteries (AZIBs) is limited by serious side reactions, such as the hydrogen evolution reaction and Zn dendrite growth. Here, the study proposes a novel adoption of a biodegradable electrolyte additive, γ‐Valerolactone (GVL), with only 1 vol.% addition (GVL‐to‐H2O volume ratio) to enable a stable Zn metal anode. The combination of experimental characterizations and theoretical calculations verifies that the green GVL additive can competitively engage the solvated structure of Zn2+ via replacing a H2O molecule from [Zn(H2O)6]2+, which can efficiently reduce the reactivity of water and inhibit the subsequent side reactions. Additionally, GVL molecules are preferentially adsorbed on the surface of Zn to regulate the uniform Zn deposition and suppress the Zn dendrite growth. Consequently, the Zn anode exhibits boosted stability with ultralong cycle lifespan (over 3500 h) and high reversibility with 99.69% Coulombic efficiency. The Zn||MnO2 full batteries with ZnSO4‐GVL electrolyte show a high capacity of 219 mAh g−1 at 0.5 A g−1 and improved capacity retention of 78% after 550 cycles. This work provides inspiration on bio‐based electrolyte additives for aqueous battery chemistry and promotes the practical application of AZIBs. [ABSTRACT FROM AUTHOR]

The practical utilization of Li metal anodes has been significantly plagued by the challenges of uncontrollable dendritic Li growth and poor interphase instability. Here, the study reports a novel strategy to strengthen interphase and give highly efficient active seeds concurrently to stabilize Li metal via a highly lithiophilic In2O3 decorated porous scaffold. In situ configurated fast‐ion‐transport Li2O‐strengthened interphase layer cooperatively with highly efficient Li13In3 nucleation induction can endow the uniform Li nucleation/growth and high Li utilization efficiency. As a result, the achieved modified Li metal manifests high Coulombic efficiency, ultrahigh rate performance (5 mA cm−2), and ultra‐long lifespan cycling durability (7975 cycles). Importantly, the established Li|LiFePO4 cells exhibit long‐term cycling durability over 600 cycles at 1 C with an ultralow decay rate of ca. 0.017% per cycle. Moreover, the Li|LiCoO2 pouch cells with ultrahigh areal capacity of ca. 3.89 mAh cm−2 also exhibit extraordinarily prolonged cycling performance with excellent capacity retention despite extremely harsh cycling conditions of low negative‐to‐positive‐capacity (N/P) ratio of ca. 1.7 and lean electrolyte of ca. 4.9 g Ah−1. This work enlightens a facile and effective avenue toward highly stable Li metal anode toward reliable practicability. [ABSTRACT FROM AUTHOR]

Sluggish kinetics of the CO2 reduction/evolution reactions lead to the accumulation of Li2CO3 residuals and thus possible catalyst deactivation, which hinders the long-term cycling stability of Li-CO2 batteries. Apart from catalyst design, constructing a fluorinated solid-electrolyte interphase is a conventional strategy to minimize parasitic reactions and prolong cycle life. However, the catalytic effects of solid-electrolyte interphase components have been overlooked and remain unclear. Herein, we systematically regulate the compositions of solid-electrolyte interphase via tuning electrolyte solvation structures, anion coordination, and binding free energy between Li ion and anion. The cells exhibit distinct improvement in cycling performance with increasing content of C-N species in solid-electrolyte interphase layers. The enhancement originates from a catalytic effect towards accelerating the Li2CO3 formation/decomposition kinetics. Theoretical analysis reveals that C-N species provide strong adsorption sites and promote charge transfer from interface to *CO22− during discharge, and from Li2CO3 to C-N species during charge, thereby building a bidirectional fast-reacting bridge for CO2 reduction/evolution reactions. This finding enables us to design a C-N rich solid-electrolyte interphase via dual-salt electrolytes, improving cycle life of Li-CO2 batteries to twice that using traditional electrolytes. Our work provides an insight into interfacial design by tuning of catalytic properties towards CO2 reduction/evolution reactions. Sluggish kinetics of the CO2 reactions lead to the accumulation of Li2CO3 residuals, which hinders the cycling stability of Li-CO2 batteries. Here, the authors reveal the catalytic role of in-situ formed C-N species in enhancing the reversibility of Li2CO3 and cycle life of Li-CO2 batteries. [ABSTRACT FROM AUTHOR]

Semiconducting metal oxide (SMO) gas sensors have emerged as an invaluable technology due to their high sensitivity and ease of fabrication. However, they have limited selectivity and require relatively high operational temperatures. Here, we present a monolithic membrane-chemoresistive sensor consisting of a hierarchical metal oxide (MO) and a metal--organic framework (MOF) layer. Both layers were made by sequential aerosol deposition of SnO2 and ZnO nanoparticles, with the latter being thereafter converted to zeolitic imidazolate framework (ZIF-8) by chemical vapour conversion. The SnO2 fractal network provides a high surface area for chemical sensing, while the multi-scale porous ZIF-8 membrane offers a controlled gateway for gas molecule diffusion. Notably, our hierarchical dual-layer architecture can tune the analyte sensor response time, allowing discrimination of a variety of gases, including NO2, ethanol, acetone, methanol, propane, and ethyl benzene. Density Functional Theory (DFT) calculations were implemented to gain further insights into the selectivity mechanism revealing the key role of surface adsorption sites. This approach enables us to develop unique response profiles, fingerprinting the presence of specific gas molecules, with application ranging from industrial safety to environmental monitoring and medical diagnostics. [ABSTRACT FROM AUTHOR]

Two-dimensional materials have been considered as novel anode materials for LIBs because of their large surface area, small volume change, and low Li diffusion barrier. Among them, the two-dimensional material SixGey has many excellent properties as an anode. However, Ge is expensive and not suitable for mass production. Therefore, proper Ge doping is of great significance to improve performance and reduce cost. Herein, we systematically study the effect of Ge doping and its concentration on the structure and electrochemical performance of two-dimensional SixGey by density functional theory (DFT) calculations. The incorporation of low concentration Ge can improve the horizontal and vertical diffusion ability of Li atoms compared to silicene. However, excessive Ge will increase the horizontal diffusion energy barrier of Li and reduce the theoretical capacity, where Si6Ge2 has a relatively high theoretical capacity and a low diffusion energy barrier. In addition, fully lithiated 2D SixGey shows poor electrical conductivity and increasing Ge concentration seems to be effective in improving the electrical conductivity of the material. This study will provide significant theoretical guidance for the design and preparation of two-dimensional silicon-based materials. [ABSTRACT FROM AUTHOR]

Chemiresistive sensing of gas molecules has been widely investigated for application in medical diagnostics and environmental monitoring, showing high sensitivity and low limits of detection toward various volatile organic compounds. While metal oxide semiconductors offer numerous advantages, such as ease of fabrication, high sensitivity, and fast response times, they often suffer of high insufficient selectivity. Here, we report the engineering of a low-temperature sensing platform consisting of nanostructured zeolitic imidazolate framework (ZIF-8) metal organic frameworks (MOFs) over InP semiconducting nanowire (NW) arrays. These devices were fabricated via top-down etching of InP NW arrays, aerosol deposition of flame-made ZnO nanoparticles, and their chemical vapor conversion to ZIF-8. The presence of ZIF-8 significantly enhances the device sensitivity over that of the pristine InP NW arrays by providing a high density of adsorption sites and faster reduction kinetics. Our optimal sensors can detect NO2 in a large concentration range from 0.1 to 8 ppm, in addition to showing relatively higher responses toward various gas molecules, including CO2, methanol, ethanol, acetone, and propane, in comparison with pristine InP NW sensors. Given the large family of MOFs with controllable pore size and chemical composition, our findings provide a flexible approach for engineering the selectivity of highly sensitive and miniaturized gas sensors for integration in miniaturized devices. [ABSTRACT FROM AUTHOR]

The instability of molecular electrodes under oxidative/reductive conditions and insufficient understanding of the metal oxide-based systems have slowed down the progress of H2-based fuels. Efficient regeneration of the electrode's performance after prolonged use is another bottleneck of this research. This work represents the first example of a bifunctional and electrochemically regenerable molecular electrode which can be used for the unperturbed production of H2 from water. Pyridyl linkers with flexible arms (–CH2–CH2–) on modified fluorine-doped carbon cloth (FCC) were used to anchor a highly active ruthenium electrocatalyst [RuII(mcbp)(H2O)2] (1) [mcbp2− = 2,6-bis(1-methyl-4-(carboxylate)benzimidazol-2-yl)pyridine]. The pyridine unit of the linker replaces one of the water molecules of 1, which resulted in RuPFCC (ruthenium electrocatalyst anchored on –CH2–CH2–pyridine modified FCC), a high-performing electrode for oxygen evolution reaction [OER, overpotential of ∼215 mV] as well as hydrogen evolution reaction (HER, overpotential of ∼330 mV) at pH 7. A current density of ∼8 mA cm−2 at 2.06 V (vs. RHE) and ∼−6 mA cm−2 at −0.84 V (vs. RHE) with only 0.04 wt% loading of ruthenium was obtained. OER turnover of >7.4 × 103 at 1.81 V in 48 h and HER turnover of >3.6 × 103 at −0.79 V in 3 h were calculated. The activity of the OER anode after 48 h use could be electrochemically regenerated to ∼98% of its original activity while it serves as a HE cathode (evolving hydrogen) for 8 h. This electrode design can also be used for developing ultra-stable molecular electrodes with exciting electrochemical regeneration features, for other proton-dependent electrochemical processes. [ABSTRACT FROM AUTHOR]

Aqueous alkali and multivalent metal-ion batteries are practically advantageous for large-scale energy storage because of intrinsic safety and environmental friendliness. Drawbacks, however, include low energy density and short life because of limited electrochemical stability windows (ESWs) of aqueous electrolytes and rapid degradation of electrode materials with high water activity. Despite significant research, including water-in-salt and electrolyte additive(s), directed to the electrolyte to extend ESWs and to boost electrode stability, the practical application remains limited because of the present high cost and generally unsatisfactory performance. Although alkali and multivalent metal ions can have different coordinating structures with solvents and anions, electrolyte design strategies share fundamental mechanisms in either extending ESWs or achieving a passivation layer on the electrode material(s). Future development of aqueous batteries, therefore, is dependent on a systematic understanding and analysis of electrolyte research. Here, we report for the first time a systematic review of the design and engineering of emerging water-based electrolytes for boosted aqueous rechargeable batteries (ARBs) performance. We present a comparative summary of electrochemical stability windows and electrode/electrolyte interphases for five (5) electrolyte types; appraise strategies and the resulting impact of electrolyte properties on electrode interfacial stability; analyze in situ generated electrode/electrolyte interphases; classify advantages and drawbacks of selected strategies; and provide a perspective on future developments in aqueous alkali and multivalent metal-ion batteries, together with methods for the study of both electrolyte and derived interphase(s). We conclude that (1) the design of electrolytes of high concentration and hybrid and eutectic solvents are practically promising for high energy density ARBs; (2) there is a need to improve design for longer cycling life of ARBs; (3) research addresses boosting ESW of the electrolyte; and (4) it increased the understanding of the electrode/electrolyte interface stability via new electrode/electrolyte interphase structures. This review will be of benefit in the practical design of electrolyte(s) for aqueous batteries for high performance and, therefore, of interest to researchers and manufacturers. [ABSTRACT FROM AUTHOR]

Aqueous Zn‐Iodine (I2) batteries are attractive for large‐scale energy storage. However, drawbacks include, Zn dendrites, hydrogen evolution reaction (HER), corrosion and, cathode "shuttle" of polyiodines. Here we report a class of N‐containing heterocyclic compounds as organic pH buffers to obviate these. We evidence that addition of pyridine /imidazole regulates electrolyte pH, and inhibits HER and anode corrosion. In addition, pyridine and imidazole preferentially absorb on Zn metal, regulating non‐dendritic Zn plating /stripping, and achieving a high Coulombic efficiency of 99.6 % and long‐term cycling stability of 3200 h at 2 mA cm−2, 2 mAh cm−2. It is also confirmed that pyridine inhibits polyiodines shuttling and boosts conversion kinetics for I−/I2. As a result, the Zn‐I2 full battery exhibits long cycle stability of >25 000 cycles and high specific capacity of 105.5 mAh g−1 at 10 A g−1. We conclude organic pH buffer engineering is practical for dendrite‐free and shuttle‐free Zn‐I2 batteries. [ABSTRACT FROM AUTHOR]

Room‐temperature detection of volatile organic compounds in particle‐per‐billion concentrations is critical for the development of wearable and distributed sensor networks. However, sensitivity and selectivity are limited at low operating temperatures. Here, a strategy is proposed to substantially improve the performance of semiconductor sensors. Tunable oxygen vacancies in thick 3D networks of metal oxide nanoparticles are engineered using deep ultraviolet photoactivation. High selectivity and sensitivity are achieved by optimizing the electronic structure and surface activity while preserving the 3D morphology. Cross‐sectional depth analysis reveals oxygen vacancies present at various depths (≈24% at a depth of 1.13 µm), with a uniform distribution throughout the thick films. This results in ≈58% increase in the sensitivity of ZnO to 20‐ppb ethanol at room temperature while ≈51% and 64% decrease in the response and recovery times, respectively. At an operating temperature of 150 °C, oxygen‐vacant nanostructures achieve a lower limit of detection of 2 ppb. Density functional theory analysis shows that inducing oxygen vacancies reduces activation energy for ethanol adsorption and dissociation, leading to improved sensing performance. This scalable approach has the potential for designing low‐power wearable chemical and bio‐sensors and tuning the activity and band structure of porous, thick oxide films for multiple applications. [ABSTRACT FROM AUTHOR]

Several transition metal oxides and hydroxides have been reported as active electrocatalysts towards the oxidation of 5-hydroxymethyl furfural (HMF), an important biomass-derived compound for downstream sustainable chemical and transport fuel production. However, few studies have investigated the activity descriptors influencing the reactivity and selectivity of these materials towards HMF electrooxidation (HMFOR). Herein, Co, Ni and Cu-based Prussian blue analogue (PBA) electrocatalysts were systematically investigated to identify the intrinsic electronic contributions of these redox species towards HMF electrooxidation activity. Cu-phase PBAs exhibited the highest faradaic efficiency of 97.4%, followed by Co-phase (90.5%) and Ni-phase (82.6%) PBAs towards generating 2,5-furandicarboxylic acid (FDCA) at 1.42 V vs. RHE in 1.0 M KOH. This activity trend is found to be influenced by the amount of nucleophilic OH* species expressed on the electrocatalyst's surface. A higher expression of these surface species results in a lower activation energy barrier for the rate limiting step, leading to increased selectivity towards FDCA. Analysis of the bulk electronic properties shows that a strong M–O bond covalency and high d-orbital occupancy contribute to this high expression of electrophilic sites. These findings establish a basis for rationalising the origins of FDCA selectivity in HMFOR catalysts, which importantly eschews using catalysts with high oxygen evolution reaction (OER) activity as a prerequisite for high HMFOR performance. [ABSTRACT FROM AUTHOR]

Establishing generic catalyst design principles by identifying structural features of materials that influence their performance will advance the rational engineering of new catalytic materials. In this study, by investigating metal‐substituted manganese oxide (spinel) nanoparticles, Mn3O4:M (M=Sr, Ca, Mg, Zn, Cu), we rationalize the dependence of the activity of Mn3O4:M for the electrocatalytic oxygen reduction reaction (ORR) on the enthalpy of formation of the binary MO oxide, ΔfH°(MO), and the Lewis acidity of the M2+ substituent. Incorporation of elements M with low ΔfH°(MO) enhances the oxygen binding strength in Mn3O4:M, which affects its activity in ORR due to the established correlation between ORR activity and the binding energy of *O/*OH/*OOH species. Our work provides a perspective on the design of new compositions for oxygen electrocatalysis relying on the rational substitution/doping by redox‐inactive elements. [ABSTRACT FROM AUTHOR]

Closing both the carbon and nitrogen loops is a critical venture to support the establishment of the circular, net‐zero carbon economy. Although single atom catalysts (SACs) have gained interest for the electrochemical reduction reactions of both carbon dioxide (CO2RR) and nitrate (NO3RR), the structure–activity relationship for Cu SAC coordination for these reactions remains unclear and should be explored such that a fundamental understanding is developed. To this end, the role of the Cu coordination structure is investigated in dictating the activity and selectivity for the CO2RR and NO3RR. In agreement with the density functional theory calculations, it is revealed that Cu‐N4 sites exhibit higher intrinsic activity toward the CO2RR, whilst both Cu‐N4 and Cu‐N4−x‐Cx sites are active toward the NO3RR. Leveraging these findings, CO2RR and NO3RR are coupled for the formation of urea on Cu SACs, revealing the importance of *COOH binding as a critical parameter determining the catalytic activity for urea production. To the best of the authors' knowledge, this is the first report employing SACs for electrochemical urea synthesis from CO2RR and NO3RR, which achieves a Faradaic efficiency of 28% for urea production with a current density of −27 mA cm–2 at −0.9 V versus the reversible hydrogen electrode. [ABSTRACT FROM AUTHOR]