Ag-Au Core-Shell Triangular Nanoprisms for Improving p-g-C3N4 Photocatalytic Hydrogen Production.

Yali Guo,Juan Hou,Anzhou Xu,Xuhong Guo,Qingcui Liu,Hailong Li

doi:10.3390/nano11123347

Abstract

Ag–Au core–shell triangular nanoprisms (Ag@Au TNPs) have aroused extensive research interest in the field of hydrogen evolution reaction (HER) due to their strong plasmon effect and stability. Here, Ag@Au TNPs were fabricated by the galvanic-free replacement method. Then, we loaded them on protonated g-C3N4 nanoprisms (P–CN) by the electrostatic self-assembly method as an efficient plasmonic photocatalyst for HER. The hydrogen production rate of Ag@Au TNPs/P–CN (4.52 mmol/g/h) is 4.1 times higher than that of P–CN (1.11 mmol/g/h) under simulated sunlight irradiation, making it the most competitive material for water splitting. The formed Schottky junction helps to trap the hot electrons generated from Ag@Au TNPs, and the well-preserved tips of the Ag@Au TNPs can effectively generate an electromagnetic field to inhibit the photogenerated electron–holes pairs recombination. This study suggests that the rational design of Ag@Au TNPs by the galvanic-free replacement method is an effective co-catalyst for HER and boosting the additional combination of plasmonic metals and catalyst metals for the enhancement to HER.

Highlights

Photocatalysis using semiconductors is a promising method to alleviate energy crisis and environmental pollution [1]
The narrow absorption spectra and the easy recombination of photogenerated electron–hole pairs in pure g-C3 N4 greatly reduce the efficiency of photocatalytic hydrogen production [3]
These observations proved that the core–shell structure of the Ag–Au TNPs was prepared successfully

Summary

Introduction

Photocatalysis using semiconductors is a promising method to alleviate energy crisis and environmental pollution [1]. Xue et al used bimetallic a Au and Pt NPs co-decorated g-C3 N4 plasmonic photocatalyst to demonstrate that the surface plasmon resonance (SPR) effect of Au and electron-sink function of Pt nanoparticles could improve the optical absorption property as well as photogenerated charge carriers separation of g-C3 N4 , synergistically facilitating the photocatalysis process [5]. Ag and Au have unique optical properties, the localized surface plasmon resonance (LSPR) [6]. When they come into contact with a semiconductor, a metal–semiconductor Schottky junction will be formed to trap electrons [7]. Ag is probably the most important material in plasmonics, and it is able to support a strong

Methods

Results

Conclusion