Dual‐Z‐Scheme Heterojunction for Facilitating Spacial Charge Transport Toward Ultra‐Efficient Photocatalytic H2 Production

Abstract

Solar‐driven water splitting has aroused considerable interest for developing renewable and clean energies. Recently, although Z‐scheme systems greatly improve the photocatalytic H2 production rate, the photoconversion efficiency is still far from the requirement for practical applications. Herein, based on direct Z‐scheme system photocatalysts, a direct CdS/W18O49/g‐C3N4 (CWOCN) dual‐Z‐scheme system is designed and fabricated. It is found that a dual‐Z‐scheme CWOCN system can efficiently regulate photoinduced carrier transfer by constructing two direct Z‐scheme charge transfer channels in the interior of the catalyst. Accordingly, the CWOCN dual‐Z‐scheme system shows an outstanding H2 production activity of 11 658 μmol g−1 h−1 without any sacrificial agents, which is about three times higher than that of CdS/W18O49 Z‐scheme nanosheets. In addition, this dual‐Z‐scheme system exhibits a high apparent quantum efficiency of 26.73% and good stability, which can keep the H2 production rate unchanged for 24 h. The design of the dual‐Z‐scheme system ensures the efficient transmission of photogenerated carriers and further optimizes the structure of the Z‐scheme system.