Developing low‐cost and high‐activity pH‐universal hydrogen evolution reaction (HER) catalysts is very crucial to the industrialization of water electrolysis. However, the high price, low yield, and poor stability of current HER catalysts make them difficult to meet practical requirements. Herein, a plasma spraying technique is employed to prepare self‐supported Cu catalysts with tensile strain for the first time. The tensile strain upshifts the d‐band of Cu, improves the water dissociation and H* adsorption, eventually improves the intrinsic HER catalytic activity. As such, Cu electrode achieves overpotentials of 182 mV in 0.5 m H2SO4, 261 mV in 1 M PBS, and 121 mV in 1 M KOH at 10 mA cm–2. In addition, Cu electrode also performs well at high current densities, the overpotentials at 1 A cm–2 are much lower than those of Pt foil in acid, neutral, and alkaline solutions.

High-entropy carbide (HEC) is a promising alternative to precious metal catalysts for the hydrogen evolution reaction (HER). However, the preparation of nanoscale HECs is a great challenge although many methods have been developed to prepare bulk HEC materials. Herein, an electrical discharge induced bulk-to-nanoparticle transformation method is reported, by which well dispersed sub-10 nm high entropy (MoWVNbTa)C nanoparticles with high-density surface defects can be directly obtained by centrifugation of the waste liquid produced during wire-cut electrical discharge machining of bulk HEC. The resultant HEC nanoparticles exhibit excellent catalytic activity and durability for HER, which is attributed to the combination of unique microstructure generated during the extremely nonequilibrium thermodynamic process and enhanced electronic effects induced by high configurational entropy. This facile and cost-effective bulk-to-nanoparticle transformation method can be extended to other conductive materials and shed light on the development of high-performance catalysts.

As a metal-free photocatalyst, graphitic carbon nitride (g-CN) shows great potential for photocatalytic water splitting, although its performance is significantly limited by structural defects due to incomplete polymerization. In the present work, we successfully synthesize highly conjugated g-CN nanofoam through an iodide substitution technique. The product possesses a high polymerization degree, low defect density, and large specific surface area; as a result, it achieves a hydrogen evolution rate of 9.06 mmol h–1 g–1 under visible light irradiation, with an apparent quantum efficiency (AQE) of 18.9% at 420 nm. Experimental analysis and theoretical calculations demonstrate that the recombination of photogenerated carriers at C–NH x defects was effectively depressed in the nanofoam, giving rise to the high photocatalytic activity.

Bismuth porous nanosheets (Bi PNSs) were synthesized via a three-step process in the absence of any surfactants and templates. As a catalyst for electrochemical CO2 electroreduction, Bi PNSs show high selectivity to formic acid with the maximum Faraday efficiency of 95.31% and maintain more than 80% Faraday efficiency over a wide voltage range of 1100 mV. The excellent performance of Bi PNSs was found to originate from the abundant kink sites on the pore walls, which have appropriate affinity to intermediates and reduce the energy barriers for CO2 electroreduction. Our work demonstrates that a clean synthetic route is advantageous to the growth of a unique nanostructure that possesses high catalytic activity.

Developing highly active and low-cost catalysts for the oxygen reduction reaction (ORR) is critical for renewable energy devices such as metal−air cells and fuel cells. In this work, we report an active ORR catalyst, Ag clusters with adatoms, which can be facilely produced by a pulse electrolysis method. The silver adatom on the silver cluster can reduce the coordination number, upshift the Ag d-band center, lower the ORR reaction barrier, and eventually transform the inactive Ag into a highly active catalyst. As a result, the catalyst exhibits high activity and stability, which are superior to ever-reported silver-based catalysts and even the commercial Pt/C catalyst.