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The catalyst‐reconstruction makes it challenging to clarify the practical active sites and unveil the actual reaction mechanism during the CO2 electroreduction reaction (CO2RR). However, currently the impact of the electrolyte microenvironment in which the electrolyte is in contact with the catalyst is overlooked and might induce a chemical evolution, thus confusing the reconstruction process and mechanism. In this work, the carbonate adsorption properties of metal oxides were investigated, and the mechanism of how the electrolyte carbonate affect the chemical evolution of catalysts were discussed. Notably, Bi2O3 with weak carbonate adsorption underwent a chemical reconstruction to form the Bi2O2CO3/Bi2O3 heterostructure. Furthermore, in situ and ex situ characterizations unveiled the formation mechanism of the heterostructure. The in situ formed Bi2O2CO3/Bi2O3 heterostructure with strong electron interaction served as the highly active structure for CO2RR, achieving a formate Faradaic efficiency of 98.1 % at −0.8 Vvs RHE. Theoretical calculations demonstrate that the significantly tuned p‐orbit electrons of the Bi sites in Bi2O2CO3/Bi2O3 optimized the adsorption of the intermediate and lowered the energy barrier for the formation of *OCHO. This work elucidates the mechanism of electrolyte microenvironment for affecting catalyst reconstruction, which contributes to the understanding of reconstruction process and clarification of the actual catalytic structure. [ABSTRACT FROM AUTHOR]

The water‐soluble salt‐template technique holds great promise for fabricating 3D porous materials. However, an equipment‐free and pore‐size controllable synthetic approach employing salt‐template precursors at room temperature has remained unexplored. Herein, we introduce a green room‐temperature antisolvent precipitation strategy for creating salt‐template self‐assembly precursors to universally produce 3D porous materials with controllable pore size. Through a combination of theoretical simulations and advanced characterization techniques, we unveil the antisolvent precipitation mechanism and provide guidelines for selecting raw materials and controlling the size of precipitated salt. Following the calcination and washing steps, we achieve large‐scale and universal production of 3D porous materials and the recycling of the salt templates and antisolvents. The optimized nitrogen‐doped 3D porous carbon (N‐3DPC) materials demonstrate distinctive structural benefits, facilitating a high capacity for potassium‐ion storage along with exceptional reversibility. This is further supported by in situ electrochemical impedance spectra, in situ Raman spectroscopy, and theoretical calculations. The anode shows a high rate capacity of 181 mAh g−1 at 4 A g−1 in the full cell. This study addresses the knowledge gap concerning the room‐temperature synthesis of salt‐template self‐assembly precursors for the large‐scale production of porous materials, thereby expanding their potential applications for electrochemical energy conversion and storage. [ABSTRACT FROM AUTHOR]

It is vitally important to develop highly active, robust and low‐cost transition metal‐based electrocatalysts for overall water splitting in neutral solution especially at large current density. In this work, amorphous Mo‐doped NiS0.5Se0.5 nanosheets@crystalline NiS0.5Se0.5 nanorods (Am−Mo−NiS0.5Se0.5) was synthesized using a facil one‐step strategy. In phosphate buffer saline solution, the Am−Mo−NiS0.5Se0.5 shows tiny overpotentials of 48 and 209 mV for hydrogen evolution reaction (HER), 238 and 514 mV for oxygen evolution reaction (OER) at 10 and 1000 mA cm−2, respectively. Moreover, Am−Mo−NiS0.5Se0.5 delivers excellent stability for at least 300 h without obvious degradation. Theoretical calculations revealed that the Ni sites in the defect‐rich amorphous structure of Am−Mo−NiS0.5Se0.5 owns higher electron state density and strengthened the binding energy of H2O, which will optimize H adsorption/desorption energy barriers and reduce the adsorption energy of OER determining step. [ABSTRACT FROM AUTHOR]

Tuning the electronic states near the Fermi level can effectively facilitate the reaction kinetics. However, elucidating the role of a specific electronic state of metal oxide in simultaneously regulating the CO2 electroreduction reaction (CO2RR) and competing hydrogen evolution reaction (HER) is still rare, making it difficult to accurately predict the practical CO2RR performance. Herein, replacing the Zn site by heteroatoms with different outer electrons (Mo and Cu) is found to tune both occupied and unoccupied orbitals near the Fermi level of ZnO. Moreover, the different electronic states significantly modulate both CO2RR and HER activity with a totally inverse trend, thus dramatically tuning the practical CO2RR performance. In parallel, the correlation between electronic states, reaction free energies and practical activity is demonstrated. This work provides a possibility for engineering efficient CO2RR eletrocatalysts through tunable composition and electronic structures. [ABSTRACT FROM AUTHOR]

Cu2O is a typical photoelectrocatalyst for sustainable hydrogen production, while the fast charge recombination hinders its further development. Herein, Ni2+ cations have been doped into a Cu2O lattice (named as Ni‐Cu2O) by a simple hydrothermal method and act as electron traps. Theoretical results predict that the Ni dopants produce an acceptor impurity level and lower the energy barrier of hydrogen evolution. Photoelectrochemical (PEC) measurements demonstrate that Ni‐Cu2O exhibits a photocurrent density of 0.83 mA cm−2, which is 1.34 times higher than that of Cu2O. And the photostability has been enhanced by 7.81 times. Moreover, characterizations confirm the enhanced light‐harvesting, facilitated charge separation and transfer, prolonged charge lifetime, and increased carrier concentration of Ni‐Cu2O. This work provides deep insight into how acceptor‐doping modifies the electronic structure and optimizes the PEC process. [ABSTRACT FROM AUTHOR]