Efficient charge separation is critical for the enhancement of photocatalytic activity for hydrogen generation. The porous Cd 1-x Zn x S nanosheets with twinned phase junctions were synthesized by the cation-exchange approach of inorganicorganic hybrid ZnS-diethylenetriamine nanoflakes with cadmium ions. With the synergy of the phase junctions induced by nano twins and porous structure, the hydrogen evolution average rate over the optimal sample Cd 0.5 Zn 0.5 S photocatalyst reaches 14.44 mmol h −1 g −1 without noble metal loading under visible light irradiation, corresponding to apparent quantum efficiency of 37.3% at 420 nm and solar-to-hydrogen energy conversion efficiency of 3.46%. On the one hand, twin-induced phase junctions can improve the separation efficiency of photoelectron-hole pairs, on the other hand, the large specific surface area ascribed to the porous nanosheet can effectively improve the light absorption capacity of photocatalysis, and provide more surface active sites. This study could provide a facile approach to design and fabricate advanced materials with porous twinned phase junctions for photocatalytic applications and optoelectronic devices.

Oxygen evolution reaction (OER), as a multi‐step coupled anode reaction, is more sluggish in kinetics than electrocatalytic hydrogen evolution reaction (HER). In order to overcome the potential barrier in OER, it is necessary to develop high‐efficient non‐noble metal catalysts for energy utilization. In this work, several NiCo‐ZIF materials with different molar ratios of Ni and Co were prepared by doping Ni2+ in the preparation of ZIF‐67 via a simple room temperature stirring method. After that, NiCo‐ZIF was calcined at 350°C in a muffle furnace to obtain corresponding Ni‐doped Co3O4 (Ni‐Co3O4). Ni‐Co3O4 catalyst exhibits a low overpotential (η ≈ 203 mV @10 mA cm−2), a small Tafel slope (111.0 mV dec−1) and prominent stability for OER in 1 M KOH solution, which is higher than for a commercially available Ir/C electrocatalyst (η ≈ 350 mV @10 mA cm−2). The higher electrochemical performance should be largely ascribed to the introduction of oxygen vacancies resulting from the Ni doping, which leads to the improved electrochemical active surface area (122.81 mF cm−2) and the topological structure of the dodecahedron, which is in favor of the good contact area between the catalyst and the electrolyte. The design and synthesis of ZIF‐derived catalyst in this work create a significative method to prepare efficient OER electrocatalysts.

The investigation of efficient, durable and highly stable non-noble metal multifunctional electrocatalysts is of great importance in hydrogen evolution reaction (HER) and has great potential to relieve energy issues. In...

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