Rational Synthesis of Metal–Organic Framework-Derived Noble Metal-Free Nickel Phosphide Nanoparticles as a Highly Efficient Cocatalyst for Photocatalytic Hydrogen Evolution

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• 作者：D. Praveen Kumar ; Jiha Choi ; Sangyeob Hong ; D. Amaranatha Reddy ; Seunghee Lee ; Tae Kyu Kim
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2016
• 出版时间：December 5, 2016
• 年：2016
• 卷：4
• 期：12
• 页码：7158-7166
• 全文大小：719K
• ISSN：2168-0485

文摘

Facile preparation of metal–organic framework (MOF) derived earth-abundant nickel phosphide (Ni<sub>2sub>P) by a simple, cost-effective procedure is described. Ni<sub>2sub>P is recognized as a suitable replacement for expensive noble metal cocatalysts used for H<sub>2sub> production by water splitting. Ni<sub>2sub>P nanoparticles were used to prepare a Ni<sub>2sub>P/CdS composite with improved photocatalytic properties. Crystal structure and surface morphology studies showed that Ni-MOF spheres readily transform into Ni<sub>2sub>P particles, and TEM images indicated the presence of Ni<sub>2sub>P nanoparticles on CdS. The optical properties and charge carrier dynamics of the composite material exhibited better visible light absorption and improved suppression of charge carrier recombination. X-ray photoelectron spectra confirmed the presence of Ni<sub>2sub>P on CdS. The synthesized materials were tested for photocatalytic hydrogen production with lactic acid as a scavenger under irradiation in a solar simulator. The rate of H<sub>2sub> production with Ni<sub>2sub>P/CdS was 62 times greater than that with pure CdS. The superior activity of the composite material is attributed to the ability of Ni<sub>2sub>P to separate the photoexcited charge carriers from CdS and provide good electrical conductivity. The optimized composite material also exhibited better photocatalytic activity than Pt cocatalyzed CdS. Based on the experimental results, a possible electron–hole transfer mechanism is proposed.