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Oxygen evolution reaction (OER) is a key process for electrochemical water splitting due to its intrinsic large overpotential. Recently, layered double hydroxides (LDHs), especially NiFe-LDH, have been regarded as highly performed electrocatalysts for OER in alkaline condition. Here we first present a new class of NiLa-LDH electrocatalyst synthesized by an electrochemical process for efficient water splitting. The as-prepared NiLa-LDH nanosheet arrays (NSAs) give remarkable electrochemical activity and durability under alkaline environments, with a low overpotential of 209 mV for OER to deliver a current density of 10 mA cm−2, surpassing most of previous reported LDHs eletrocatalysts. The presence of NiLa-LDH in this work extends the studies about LDHs-based electrocatalysts, which will benefit the development of electrochemical energy storage and conversion systems.

Electrochemical CO2reduction reaction (CO2RR) to high-value compounds has attracted considerable attention; however, studies on intrinsic active sites under operating conditions remain controversial. Herein, we report a Bi/Bi2O2CO3thin-nanosheets electrocatalyst (denoted as Bi/BOC TNS), which gives a formate Faradaic efficiency of 92.1% and a formation rate of 845.2 μmol h−1cm−2. A strong electron transfer at the interface induces a redistribution of local charge and enhances the interaction of interface polarization. The comprehensive investigations based on in situexperimental studies and density functional theory calculations confirm that the interface structure (Bi0−Biδ+) serves as the intrinsic active site toward CO2to formate. Specifically, a water molecule undergoes dissociation to provide protons at Bi0, while the CO2∗ species adsorbed at Biδ+experiences C−H formation to generate the key intermediate (∗OCHO). This work demonstrates the dynamic structure reconstruction of electrocatalyst and reveals the synergistic catalysis, which is of great significance for researches on highly efficient CO2RR electrocatalysts.

This diagram depicts the different performances of the two Cu2O catalysts with/without CuBTC modification in CO2electroreduction, which can be ascribed to the introduced CuBTC shell maintaining the active Cu+under reducing conditions.

The excessive consumption of fossil fuels has led to a rapid surge in atmospheric CO2concentration, triggering severe energy crises and environmental concerns. In this context, photoelectrochemical (PEC) technology for CO2reduction is perceived as a highly appealing resolution, due to its integration of the advantages offered by both photocatalysis and electrocatalysis. Undoubtedly, the photocathode plays a pivotal role within the PEC CO2reduction system. Among various catalysts, copper (Cu)-based photocathodes have garnered significant attention owing to their low toxicity, affordability, advantageous band gap and distinctive active sites that enable the conversion of CO2into a diversity of reduction products including carbon monoxide (CO), formic acid (HCOOH), methane (CH4), ethylene (C2H4), ethanol (C2H5OH) and so on. This review primarily delves into the current developments of Cu-based photocathodes in PEC CO2reduction, encompassing aspects like material fabrication processes and modification techniques. Subsequently, an analysis is presented regarding the reaction mechanisms underlying different CO2conversion products. Finally, an anticipatory perspective is provided regarding future research in the field of PEC CO2reduction. This review enables researchers to promptly capture the latest advancements of Cu-based photocathode for PEC CO2reduction, offers valuable insights for future research on the design and synthesis of Cu-based photocathode, and provides a guideline to achieve enhanced improvements in PEC CO2conversion.