All-In-One Detection, Removal and Recovery of Hg2+ in Industrial Wastewater with Plasmonic Schottky Heterostructures

Abstract

The effective governance of Hg2+ in environmental wastewater is of profound significance to deal with the global pollution issues. However, the present methodologies usually only focused on a single function of either detection or removal, which encounters severe secondary pollution and cumbersome operation cost, while the integration of Hg2+ detection, removal, and recovery in one process is barely realized. In this study, an All-In-One photoelectrochemical system is built combining the detection, removal, and recovery of Hg2+ pollutant in a single process, by ingeniously developing a fundamental principle, namely alloying-induced plasmonic quenching mechanism in Schottky heterostructures. Briefly, the high-efficiency removal and recovery of Hg2+ in wastewater is realized via the favorable alloying of Hg in Ag nanoparticles that well-dispersed on the free-standing WO3 nanoplate networks. The formation of Ag–Hg alloy future leads to a remarkable plasmonic quenching effect of the Ag nanoparticles, which is used to modulate the photoelectrochemical singles to realize the high-precision detection. Through this ingenious design, an ultralow Hg2+ detection limit of 0.296 nm is achieved with a broad detection range up to 12.5 µm, and meanwhile realize a removal/recovery rate of 100% in single Hg2+ solution and 97 ± 2% in industrial wastewater with multiple contamination ions. The detection and removal/recovery performance parameters reported in the study are much better as compared to the recently reported single function detection or removal/recovery systems. This work opens a fresh avenue in tackling the problem of heavy metal pollution using plasmonic Schottky heterostructure based All-In-One systems.