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Efficient Visible-Light-Driven Splitting of Water into Hydrogen over Surface-Fluorinated Anatase TiO₂ Nanosheets with Exposed {001} Facets/Layered CdS–Diethylenetriamine Nanobelts

Dai, Kai, Lv, Jiali, Zhang, Jinfeng, Zhu, Guangping, Geng, Lei, Liang, Changhao
ACS sustainable chemistry & engineering 2018 v.6 no.10 pp. 12817-12826
cadmium, electric current, energy, hydrogen, hydrogen production, models, nanoparticles, nanosheets, photocatalysis, photocatalysts, photoluminescence, pollution, titanium dioxide
Cadmium sulfide (CdS), is one of the superior visible-light-driven photocatalysts, and has a prosperous and practical future in hydrogen (H₂) production from water splitting for addressing environmental problems, such as environmental contamination and energy shortage. But the inherent serious drawback of photocorrision always limits its photocatalytic performance. Here, we fabricated a layered nanojunction to enhance the H₂ generation of the surface-fluorinated TiO₂/CdS–diethylenetriamine (F–TiO₂/CdS–DETA) system. The loading of F–TiO₂ nanosheets (NSs) with exposed {001} facets on inorganic–organic CdS–DETA nanobelts (NBs) greatly improves the interfacial contact. The layered nanojunction structure efficiently inhibits the charge carriers’ recombination and enhances the H₂ production stability of CdS. At an optimal ratio of 30%F–TiO₂, the F–TiO₂/CdS–DETA composite exhibits the highest H₂ production rate of 8342.86 μmol h–¹ g–¹, which is 6.6 times and 1.7 times as high as that of CdS nanoparticles and CdS–DETA NBs, respectively. The apparent quantum yield of the H₂ evolution system reaches 24.9% at 420 nm with a Pt cocatalyst. More importantly, the surface of the F–TiO₂ nanosheets enriches a large amount of trapping centers of photogenerated holes, which can thus efficiently promote the charge carriers’ separation and enhance the photocatalytic H₂ evolution of CdS–DETA. Also, the effective charges transfer route of F–TiO₂/CdS–DETA is also demonstrated by a photoluminescence test and photocurrent response. This work provides an ideal model for the design of stable and efficient H₂ production photocatalysts.