Ternary CdS@MoS<sub>2</sub>–Co<sub>3</sub>O<sub>4</sub> Multiheterojunction Photocatalyst for Boosting Photocatalytic H<sub>2</sub> Evolution
Lulu Zhang, Jingxuan He, Na Li, Jie Yuan, Wenjuan Li, Ping Liu, Tingjiang Yan
Abstract
Turning the carrier dynamics in heterojunction photocatalysts is a direct and effective strategy for improving the solar energy conversion efficiency of photocatalysts. Herein, we report a ternary CdS@MoS 2 –Co 3 O 4 multiheterojunction photocatalyst consisting of the p–n junction of MoS 2 –Co 3 O 4 and the type-I junction of CdS@MoS 2, wherein MoS 2 located at the frontier between CdS and Co 3 O 4 acts as an intermediate bridge. The type-I junction allows the directional transfer of photoinduced charge from CdS to MoS 2, suppressing the photocorrosion of CdS. Notably, the single-particle photoluminescence technique demonstrates the sequential one-direction hole transfer from MoS 2 to Co 3 O 4 aroused by the p–n junction, resulting in a long-lifetime charge separation in the carrier lifetime (54–58 ns). Compared to the bare CdS and type-I CdS@MoS 2, the CdS@MoS 2 –Co 3 O 4 photocatalyst affords a 347-fold and 3.5-fold enhancement of the H 2 evolution rate, a quantum efficiency of 28.6% at 450 nm, and a 20 h of long-term stability. This work provides a new understanding of the rational regulation of the charge-transfer mechanism of type-I systems by constructing multiheterojunction photocatalysts.