Efficient hydrogen production from wastewater remediation by piezoelectricity coupling advanced oxidation processes

Abstract

Efficient H₂ harvesting from wastewater instead of pure water can minimize fresh water consumption, which is expected to solve the problem of water shortage in H₂ production process and contribute to carbon neutrality in the environmental remediation, but the inevitable electron depletion caused by electron-consuming pollutants will result in an exhausted H₂ evolution reaction (HER) performance. In this paper, by coupling piezocatalysis and advanced oxidation processes (AOPs) by a MoS₂/Fe⁰/peroxymonosulfate (PMS) ternary system, extensive types of wastewater achieved considerable H₂ generation, which exceeded the yield in pure water with synchronous advanced degradation of organic pollutants. In addition, profiting from the crucial bridging role of PMS, the H₂ yield in nitrobenzene wastewater after the introduction of PMS-based AOPs increased 3.37-fold from 267.7 μmol·g^-1·h^-1 to 901.0 μmol·g^-1·h^-1 because the presence of PMS both thermodynamically benefited MoS₂ piezocatalytic H₂ evolution and eliminated the electron depletion caused by organic pollutants. By this way, the original repressed H₂ evolution performance in substrate of wastewater not only was regained but even showed a significant enhancement than that in pure water (505.7 μmol·g^-1·h^-1). Additionally, the cyclonic piezoelectric reactor was preliminarily designed for future industrialization. This strategy provided a valuable path for the recycling of actual wastewater by fuel production and synchronous advanced treatment.