Heterostructured metal sulfide (ZnS-CuS-CdS) photocatalyst for high electron utilization in hydrogen production from solar water splitting

H-2-production from solar water splitting attracts great attention due to its cleanness and renewable characteristics in converting solar energy into chemical energy. A sequential fabrication approach for metal sulfide photocatalysts consisting of three components (ZnS, CuS, and CdS) is designed in order to achieve efficient charge flows by introducing CuS and CdS on ZnS surfaces. ZnS particles are firstly synthesized as a base material through colloidal precipitation, and then the ZnS surfaces are sequentially modified by adding CuS (cation exchange reaction) and CdS (ionic reaction) precursors. For the final products (ZnS-CuS-CdS), atomic compositions are carefully analyzed. The ZnS-CuS-CdS composite photocatalyst reaches a maximum H-2-production rate (837.6 mu mol/g h) at Cu 0.81 wt% and Cd 14.7 wt% under the standard solar irradiation (1 kW/m(2), AM 1.5 G) compared to the ZnS only case (13.5 mu mol/g h). This highly enhanced photocatalytic activity is due to synergistic effects of heterostructured ZnS-CuS-CdS photocatalyst which can improve charge flow and light absorption. This study shows a great possibility of manufacturing multi-component metal sulfide systems for improving H-2-production activity from solar water splitting. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.