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The electrochemical reduction of CO2 (CO2RR) has gained significant attention due to its potential to reduce carbon emissions and produce valuable fuels and chemicals. CO2RR is typically carried out in neutral or alkaline conditions, while challenges such as the carbon crossover and salt precipitate can hinder the practical application. Conducting CO2RR in acidic media presents a promising method to address these issues, although it faces the problem of low efficiency and poor catalysis stability. Regulating the interface/surface microenvironment near the catalysts is crucial to minimize the competitive hydrogen evolution reaction and enhance CO2RR activity and long‐term stability. This review outlines recent advancements in acidic CO2RR, emphasizing various microenvironment engineering strategies for optimizing the CO2RR kinetics including electrolyte composition manipulation, catalyst design, electrode modification and cell configuration optimization. Additionally, the review addresses challenges into developing practical and cost‐effective CO2RR systems. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (AZIBs) have garnered significant attention in the realm of large-scale and sustainable energy storage, primarily owing to their high safety, low cost, and eco-friendliness. Aqueous electrolytes, serving as an indispensable constituent, exert a direct influence on the electrochemical performance and longevity of AZIBs. Nonetheless, conventional aqueous electrolytes often encounter formidable challenges in AZIB applications, such as the limited electrochemical stability window and the zinc dendrite growth. In response to these hurdles, a series of advanced aqueous electrolytes have been proposed, such as "water-in-salt" electrolytes, aqueous eutectic electrolytes, molecular crowding electrolytes, and hydrogel electrolytes. This comprehensive review commences by presenting an in-depth overview of the fundamental compositions, principles, and distinctive characteristics of various advanced aqueous electrolytes for AZIBs. Subsequently, we systematically scrutinizes the recent research progress achieved with these advanced aqueous electrolytes. Furthermore, we summarizes the challenges and bottlenecks associated with these advanced aqueous electrolytes, along with offering recommendations. Based on the optimization of advanced aqueous electrolytes, this review outlines future directions and potential strategies for the development of high-performance AZIBs. This review is anticipated to provide valuable insights into the development of advanced electrolyte systems for the next generation of stable and sustainable multi-valent secondary batteries. [ABSTRACT FROM AUTHOR]

BiVO4 is an attractive photoanode material for water oxidation, but requires surface treatment to improve the energy efficiency and stability. Herein, we investigate the role of borate buffer in activating the BiVO4 photoanode. We found that trace iron impurities in the borate buffer play a critical role in activating the photoanode. By optimizing the activation conditions, the photocurrent density attains 4.5 mA cm−2 at 1.23 VRHE without any cocatalysts, alongside a high ABPE value of 1.5% at 0.7 VRHE. Our study discloses the role of iron in the activation effect of borate buffer on the BiVO4 photoanode, which has implications for other catalytic systems. [ABSTRACT FROM AUTHOR]

Bipolar membranes (BPMs) have emerged as a promising solution for mitigating CO2 losses, salt precipitation and high maintenance costs associated with the commonly used anion‐exchange membrane electrode assembly for CO2 reduction reaction (CO2RR). However, the industrial implementation of BPM‐based zero‐gap electrolyzer is hampered by the poor CO2RR performance, largely attributed to the local acidic environment. Here, we report a backbone engineering strategy to improve the CO2RR performance of molecular catalysts in BPM‐based zero‐gap electrolyzers by covalently grafting cobalt tetraaminophthalocyanine onto a positively charged polyfluorene backbone (PF‐CoTAPc). PF‐CoTAPc shows a high acid tolerance in BPM electrode assembly (BPMEA), achieving a high FE of 82.6 % for CO at 100 mA/cm2 and a high CO2 utilization efficiency of 87.8 %. Notably, the CO2RR selectivity, carbon utilization efficiency and long‐term stability of PF‐CoTAPc in BPMEA outperform reported BPM systems. We attribute the enhancement to the stable cationic shield in the double layer and suppression of proton migration, ultimately inhibiting the undesired hydrogen evolution and improving the CO2RR selectivity. Techno‐economic analysis shows the least energy consumption (957 kJ/mol) for the PF‐CoTAPc catalyst in BPMEA. Our findings provide a viable strategy for designing efficient CO2RR catalysts in acidic environments. [ABSTRACT FROM AUTHOR]