Homojunction CdS Photocatalysts with a Massive S^2–-Adsorbed Surface Phase: One-Step Facile Synthesis and High H₂-Evolution Performance

Abstract

For the traditional hexagonal CdS (h-CdS) photocatalyst, both of the efficient charge separation and rapid H2-evolution reactions are highly required for improving its H2-production efficiency. In this study, a facile noble metal-free strategy was reported to simultaneously realize the efficient charge separation and rapid interfacial H2-evolution reaction by homojunction CdS photocatalysts with a massive S2–-adsorbed surface phase in a sulfur-rich system. Herein, massive S2–-adsorbed c-CdS nanoparticles as the effective surface phase were deposited on the h-CdS photocatalyst surface by an adsorption in situ transformation strategy. The obtained c-CdS nanocrystals with a nanocrystal size of ∼5 nm and with massive S2–-ion adsorption can be homogeneously dispersed on the whole h-CdS surface to form c-CdS/h-CdS photocatalysts. Photocatalytic activity evaluation revealed that the H2-production performance of the h-CdS photocatalyst could be markedly enhanced by modifying S2–-adsorbed c-CdS nanoparticles, and the c-CdS/h-CdS (7 wt %) achieved a H2-production rate of 1789.2 μmol h–1 g–1, about 2.3 times higher than that of the h-CdS (795.1 μmol h–1 g–1). The improved H2-generation activity of c-CdS/h-CdS can be accounted by the excellent synergistic effect of c-CdS nanocrystals and S2– ions; namely, the surface homojunction of hexagonal and cubic CdS can facilitate the spatial charge separation, while numerous adsorbed S2– ions on the c-CdS nanocrystal surface can effectively function as H2-generation active centers to boost the H2 formation. This study may provide new ideas to one-step construct highly efficient photocatalysts for water splitting.

Integrated S‐Scheme Heterojunction of Amine‐Functionalized 1D CdSe Nanorods Anchoring on Ultrathin 2D SnNb2O6 Nanosheets for Robust Solar‐Driven CO2 Conversion

“…Furthermore, photoelectrochemical measurement was also conducted to reflect the charge transfer efficiency. [ 66,67 ] As displayed in Figure 7c,d, the 10%SNO/CdSe–DET composite displays the highest photocurrent and the lowest resistance over the other samples, corresponding to the enhanced separation of photoinduced carriers. These results disclose that for the SNO/CdSe–DET heterojunction more electrons and holes participate in the photocatalytic CO 2 reduction reaction.…”

One‐Step Realization of Crystallization and Cyano‐Group Generation for g‐C3N4 Photocatalysts with Improved H2 Production

“…[ 1–6 ] Photocatalytic technology has been perceived as one of the most hopeful techniques. [ 7–14 ] Among multitudinous photocatalysts, [ 15–21 ] graphitic carbon nitride (g‐C 3 N 4 ), one of the most prospective visible‐light response photocatalysts, has caught extensive attention in photocatalytic pollutant degradation, [ 22 ] hydrogen production, [ 23,24 ] and CO 2 reduction [ 25 ] due to its excellent bandgap structure and prominent thermostability. The conventional g‐C 3 N 4 was normally produced by a high‐temperature calcination process using various organic precursors (for instance, melamine, thiourea, dicyandiamide, et al).…”

A facile approach to synthesize CdS–attapulgite as a photocatalyst for reduction reactions in water

“…In the FT-IR spectrum of blank-CdS, the wavenumber at 674, 1000 and 1380 cm À1 are attribute to the typical absorption of the Cd-S bond. 51 In the spectrum of ATP, on characteristic peaks at 800 and 1032 cm À1 can ascribed to the symmetric stretching vibration of Si-O and unsymmetric stretching vibration of Si-O-Si respectively. 43 And the broad-band between 3300 and 3500 cm À1 is due to the skeletal vibrations of O-H. 43 The major characteristic vibration peaks related to CdS and ATP can be clearly found in the composites, which implying that the structure of CdS remains intact aer composited with ATP.…”