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.