The rational design of effective catalysts for sluggish oxygen evolution reactions (OERs) is desired but challenging. Nickel-iron (NiFe) (oxy) hydroxides are promising pre-electrocatalysts for alkaline OER. However, OER performances are limited by the slow reconstruction process to generate active species of high-valance NiFe oxyhydroxides. In this work, a sulfate ion (SO 4 2− ) modulated strategy is developed to boost the OER activity of NiFe (oxy)hydroxide by accelerating the electrochemical reconstruction of pre-catalyst and stabilizing the reaction intermediate of OOH* during OER. The SO 4 2− decorated NiFe (oxy)hydroxide catalyst (NF-S0.15) is fabricated via scalable anodization of NiFe foam in a thiourea-dissolved electrolyte. The experimental and theoretical investigations demonstrate the dual effect of SO 4 2− on improving OER performances. SO 4 2− leaching is favorable for the electrochemical reconstruction to form active NiFeOOH under OER condition. Simultaneously, the residual SO 4 2− adsorbed on surface can stabilize the intermediate of OOH*, and thus enhance the OER performances. As expected, NF-S0.15 delivers an ultralow overpotential of 234 mV to reach the current density of 50 mA cm −2 , a fast OER kinetics (27.7 mV dec −1 ), and a high stability for more than 100 h. This unique insights into anionic modification could inspire the development of advanced electrocatalysts for efficient OER.

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Developing a durable and efficient photocatalyst for H2 evolution is highly desirable to expedite current research on solar–chemical energy conversion. In this work, we rationally designed and synthesized a direct Z-scheme system based on three-dimensional hierarchical CdS decorated with Co9S8 nanoparticles toward photocatalytic H2 evolution. The composition, microstructure, and optical properties of the hybrids were thoroughly investigated. Photocatalytic performances revealed that the optimized CdS/Co9S8-15 composite exhibited the highest H2-evolution rate of 5.15 mmol h–1 g–1, which is approximately 6.8 and 257.5 times that of CdS and Co9S8, respectively. In addition, this novel composite catalyst also displayed long-term stability without apparent debasement in photocatalytic activity. On the basis of the analysis of UV–vis diffuse reflectance spectroscopy, photocurrent response, electrochemical impedance spectra, and photoluminescence, the reinforced H2 evolution performance of the CdS/Co9S8 samples was attributed to a synergistic effect including boosted light absorption capacity, increased separation and transfer efficiency of photogenerated electron/hole pairs, as well as much stronger reducibility of electrons in the conduction band of Co9S8. Finally, the photocatalytic mechanism for this composite was proposed and discussed in detail.

Doped BiOCl nanoplates enclosed with (001) and (110) facets were fabricated to demonstrate the role of doping in promoting spatial carrier separation.

A novel three-dimensional (3D) hierarchical flower-like Ag 3 PO 4 /SnSe 2 composite photocatalyst was successfully prepared via an in situ precipitation method. The composition, microstructure and optical properties of the Ag 3 PO 4 /SnSe 2 composites were thoroughly investigated. Nano-sized Ag 3 PO 4 particles were uniformly dispersed on the surface of 3D flower-like SnSe 2 . The obtained Ag 3 PO 4 /SnSe 2 composites presented enhanced performance for photocatalytic degradation of Rhodamine B (RhB) compared with pure Ag 3 PO 4 and SnSe 2 under visible light irradiation. The Ag 3 PO 4 /SnSe 2 -6 composite exhibited the optimal efficiency for photocatalytic decomposition of RhB, approximately 4.2 and 26 times higher than those of pure Ag 3 PO 4 and SnSe 2 . Significantly, the superior stability was also observed after four cycles. The enhanced performance of the Ag 3 PO 4 /SnSe 2 composites under visible light was ascribed to a synergistic effect including the matched energy band structures, increased light harvesting and boosted separation efficiency of photo-generated carriers. A possible photocatalytic mechanism of the composite was also discussed.