Sensitive detection of p-nitrotoluene based on a copper cluster modified carbon nitride nanosheets photoelectrochemical sensor

In this work, graphite carbon nitride nanosheets (CNNS) with an average thickness of about 1 nm were prepared by stepwise stripping, after surface modification with Cu(II) cluster, which can be applied to construct photoelectrochemical sensors for p-nitrotoluene monitoring. In the detection process, Cu(II) can effectually expedite the separation of photogenerated electron-hole pairs in CNNS, and significantly enhance photocurrent signals for the p-nitrotoluene sensing via the redox action of Cu(II)/Cu(I). More importantly, the change of photocurrent signal of the photoelectrochemical sensor (CNNS-Cu2% as the representative sample) presents a perfect linear relationship with the logarithm of p-nitrotoluene concentration in the range of 0.1–100 μmol L−1. Therefore, the constructed CNNS-Cu2% photoelectrochemical sensor can be diffusely employed for the trace detection of p-nitrotoluene in the real-time monitoring of water environmental contaminants. This work supplies a novel insight to the better design and construction of efficient and durable photoelectrochemical sensors.