Pt Nanoparticles Supported on Ultrathin Ni(OH)₂ Nanosheets for Highly Efficient Reduction of 4-Nitrophenol

Abstract

The synthesis of highly efficient heterogeneous catalysts with uniformly dispersed noble metal particles and a suitable size is crucial for various industrial applications. However, the high cost and rarity of noble metals limit their economic efficiency, making it essential to improve the catalytic performance with lower noble metal loading. Herein, a two-step method was developed for the synthesis of uniformly dispersed ~3 nm Pt nanoparticles (NPs), strongly anchored on Ni(OH)2 nanosheets (NSs), which was proven by adequate structural characterizations. XPS analysis demonstrated that Ni(OH)2 NSs with abundant oxygen vacancies provided sufficient anchor sites for Pt NPs and prevented their agglomeration. The catalytic performance of Ptn/Ni(OH)2 (n (represents the addition amount of Pt precursors during the synthesis, μmol) = 5, 10, 15, and 20) NSs with controllable Pt loading were evaluated via the reduction of 4-nitrophenol to 4-aminophenol as a model reaction. The Pt10/Ni(OH)2 NSs exhibited the best activity and stability, with a reaction rate constant of 0.02358 s−1 and negligible deterioration in ten reaction cycles. This novel synthetic method shows potentials for the synthesis of highly efficient noble-metal-supported catalysts for heterogeneous catalysis.

Keywords

• Pt/Ni(OH)₂ nanosheets
• oxygen vacancy
• heterogeneous catalysis
• reduction of 4-nitrophenol