LAUSR

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.