RETRACTED: Creating zinc vacancy within 3D hierarchical ZnIn2S4 particles for boosted photocatalytic performance towards H2 evolution reaction

Zinc atomic vacancies were created within ZnIn2S4 particles by reactive ion etching (RIE). The as-prepared ZnIn2S4 particles exhibited a flower-like 3D hierarchical structure. Zn vacancies had significant impacts on the S chemical environment but had little impact on the In chemical environment. The cubic crystal phase of ZnIn2S4 was not affected by the Zn vacancies, while the bandgap of ZnIn2S4 was gradually decreased with the increased concentration of Zn vacancies. The ZnIn2S4 particles with the optimal Zn vacancy concentration exhibited an enhanced photocatalytic H2 evolution rate, which is 2.7 times of the bare ZnIn2S4. The stability of the optimized ZnIn2S4 photocatalyst was tested. Nyquist plots and transient photocurrent plots demonstrated that, the existence of Zn vacancies resulted in a decreased charge carrier transfer resistance and an increased charge separation rate. The radical trapping experiments proved that, superoxide was the crucial active species during the photocatalytic reaction.