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.

Solvation effect enabled visualized discrimination of multiple metal ions

“…, whereas, the unconscionable discharge and accidental leakage easily cause the pollution of the water body and soil, from which the potentially toxic metals could be accumulated into the human body through the food chain. 3–5 Therefore, the World Health Organization (WHO) and many national environmental agencies have enacted regulations to strictly limit the concentration of specific metal ions in drinking water, food, and cosmetics. The pressing need for highly effective, low-cost, portable and reliable sensing analysis has given rise to the development of plenty of rapid detection methods for metal ions.…”