ZnIn2S4/In(OH)3 hollow microspheres fabricated by one-step l-cysteine-mediated hydrothermal growth for enhanced hydrogen production and MB degradation

An intervening barrier for photocatalytic water decomposition and pollutant degradation is the frustratingly quick recombination of e − - h + pairs. Delicate design of heterojunction photocatalysts by coupling the semiconductors at nanoscale with well-matched geometrical and electronic alignments is an effective strategy to ameliorate the charge separation. Here a facile and environment-friendly l -cysteine-assisted hydrothermal process under weakly alkaline conditions is demonstrated for the first time to fabricate ZnIn 2 S 4 /In(OH) 3 hollow microspheres with intimate contact, which are verified by XRD, SEM, (HR)TEM, XPS , N 2 adsorption-desorption, UV–Vis DRS and photoluminescence spectra. ZnIn 2 S 4 /In(OH) 3 heterostructure (L-cys/Zn 2+  = 4, molar ratio) with a band-gap of 2.50 eV, demonstrates the best photocatalytic performance for water reduction and MB degradation under visible light, outperforming its counterparts (In(OH) 3 and ZnIn 2 S 4 ). The excellent activity of ZnIn 2 S 4 /In(OH) 3 heterostructure arises from the intercrossed band-edge positions as well as the unique hollow structure with large surface area and wide pore-size distribution, which are beneficial for the efficient charge migration from bulk to surface as well as at the interface between ZnIn 2 S 4 and In(OH) 3 . This work provides an efficient and eco-friendly strategy for one-pot synthesis of heterostructured composites with intimate contact for photocatalytic application.