High-performance ZnIn2S4/Ni(dmgH)2 for photocatalytic hydrogen evolution: Ion exchange construction, photocorrosion mitigation, and efficiency enhancement by photochromic effect

In this work, a novel photocatalyst of ZnIn 2 S 4 /Ni(dmgH) 2 was designed by a simple chemical precipitation method and used to enhance hydrogen evolution under visible light irradiation. Along with vigorous discharges of hydrogen bubbles, an optimal rate of 36.3 mmol/g/h was reached under UV–Vis light for hydrogen evolution, nearly 4.9 times of the one from pure ZnIn 2 S 4 . The heterojunction exhibits steady hydrogen evolution capability and owns a high apparent quantum efficiency (AQE) of 20.45% under the monochromatic light at 420 nm. By coupling ZnIn 2 S 4 with Ni(dmgH) 2 , an extraordinary photochromic phenomenon was detected and attributed to the active Ni-S component in situ formed between the nickel and sulfur composites under light irradiation. The emerging sulfide benefits light absorption of the system and separation of photogenerated electron and hole pairs. Besides providing a promising photocatalyst for visible light hydrogen production, the present work is hoped to inspire new trends of catalytic medium designs and investigations.