Spontaneous Deposition of Uniformly Distributed Ruthenium Nanoparticles on Graphitic Carbon Nitride for Quantifying Electrochemically Accumulated H2O2

Main observation and conclusion Highly dispersed ultrasmall ruthenium nanoparticles with a clean surface are deposited onto graphitic carbon nitride (C 3 N 4 ‐Ru) through spontaneous redox reaction between the C 3 N 4 sheets and Ru salt without the use of any reductant. The as‐prepared C 3 N 4 ‐Ru exhibits distinct peroxidase‐like activity. A nanozyme based method is successfully developed for detecting the H 2 O 2 generated in‐situ by the two‐electron oxygen reduction strategy. The C 3 N 4 ‐Ru nanozyme can realize the detection of H 2 O 2 with a wide linear range and a low detection limit. The testing results are also compared with the conventional modified titration method, and show greater possibility for the practical detection of H 2 O 2 produced via the electrochemical oxygen reduction for its higher selectivity.