▎ 摘　　要

The development of highly efficient visible-excited charge separation photo active materials has attracted great attention for solving the global energy crisis and environmental problems. In this paper, p-type BiOBr nanoplates decorated n-type nitrogen doped graphene (BiOBr-NGR) composites are constructed by a facile wet chemical method. The formation of p-n junctions was beneficial to the efficient visible-excited charge transfer, and effectively restrains the recombination of photoinduced electron ehole pairs, resulting enhanced photoelectrochemical (PEC) performance. In particular, it is shown by means of the transient-state surface photocurrent responses that the photocurrent intensity of the asfabricated composites exhibited 2.6 times higher than that of pristine BiOBr. Based on the robust photocurrent signal, a novel PEC sensor based on BiOBr-NGR was established for sensitive and selective detection of chlorpyrifos. The as-fabricated PEC sensor demonstrates many advantages such as wide linear range (5 pg mL(-1) -11.6 ng mL(-1)), low detection limit (1.67 pg mL(-1), S/N = 3), and remarkably convenient, which provides a general format for chlorpyrifos detection in food and environment analysis. (C) 2016 Elsevier Ltd. All rights reserved.