Photoelectrochemical detection of 4-nitrophenol by sensitive Ni/Cu2O photocathode

Abstract As a typical toxic pollutant, 4-nitrophenol (4-NP) has caused a serious threat to environment. Therefore, rapid and selective detection of 4-NP, especially designing a simple and portable instrument, is significant for environmental protection and remediation. Herein, a sensitive/visible light-driven photoelectrochemical (PEC) sensor system was reasonably established for selectively detecting 4-NP via a simple Ni/Cu2O photocathode. The Ni/Cu2O photocathode exhibits the excellent PEC reduction capacity for ultra-sensitive sensing the trace 4-NP under illumination. Under optimized conditions of PEC determination, the photocurrent could be well linear with 4-NP concentration in the range of 0 to 37.5 μM, with a low detection limit of 16.0 nM. More importantly, the proposed cheap and easily recoverable Ni/Cu2O photocathode would be potentially applied for practical cathodic PEC detection of 4-NP in water samples, and act as a feasible platform for PEC degradation and mechanism analysis of other toxic chemical pollutants.