NiS as a Cocatalyst Decorated Heptazine-/Triazine-Based Carbon Nitride Coupled with Cd_0.5Zn_0.5S Solid Solution Heterojunction Photocatalysts: Efficient Interfacial Charge Transfer and Enhanced Photocatalytic Hydrogen Production Activity

Abstract

Heptazine-/triazine-based g-C 3 N 4 coupled with Cd 0.5 Zn 0.5 S solid solution heterojunction photocatalysts using NiS as a cocatalyst (CZS/HTCN−NiS) were constructed, aiming to obtain excellent photocatalytic hydrogen production performance. The electronic structure and visible light absorption property of g-C 3 N 4 were regulated by the combination of heptazine and triazine units. A traditional type-II heterojunction was formed between Cd 0.5 Zn 0.5 S and HTCN, which gave rise to a high separation efficiency and a faster transfer rate of photogenerated charge carriers, subsequently contributing to the improvement of the photocatalytic H 2 evolution activity. NiS as a cocatalyst not only could enhance the light absorption ability of CZS/HTCN but also further accelerate the charge transfer in order to boost the H 2 production performance. The optimal H 2 evolution performance of CZS/HTCN−NiS15 was achieved to be 6.77 mmol g −1 •h −1 with the highest apparent quantum efficiency of 11.88% at 450 nm. KEYWORDS: heptazine-/triazine-based g-C 3 N 4 , Cd 0.5 Zn 0.5 S solid solutions, traditional type-II heterojunction, charge transfer, photocatalytic hydrogen evolution

In situ fabrication of BiOBrxCl1−x photocatalysts with a regulated electronic structure and enhanced visible light photocatalytic performance

“…And the reference standard in which 0 V versus NHE equals −4.44 eV versus the vacuum level. 13,14 Thus, as displayed in Fig. 1d, the E VB of BiOCl was obtained by the equation: E VB = 21.22 − (15.93 − 1.90) − 4.44 = +2.75 V. Then, the conduction band energy (E CB ) of BiOCl was calculated to be +0.29 V by the formula E g = E VB − E CB .…”