UC Santa Cruz

Transition metal dichalcogenides have been attracting extensive attention as effective piezocatalysts for a wide range of applications, in particular, environmental remediation. Herein, WS2 nanoflowers with 2H-rich ultrathin petals are prepared by rapid synthesis based on magnetic induction heating (MIH) of sodium tungstate and thiourea, and the 2H phase is further enriched by Fe doping, in contrast to conventional pyrolysis that produces largely 1 T phase. Among the series, the sample prepared at 400 A for 10 s with an iron loading of ca. 0.1 wt% (3-Fe/WS2-400) exhibits the strongest piezoelectric response and greatest catalytic activity towards the selective reduction of oxygen to hydrogen peroxide under ultrasonic irradiation, reaching an ultrahigh H2O2 generation rate of 4.68 mM g⁻¹ h⁻¹ , over 47 times higher than that of bulk-like WS₂. This is due to enhanced adsorption of O2 and manipulation of the electronic band structure by Fe doping that becomes favorable for oxygen reduction to H2O2, as manifested in theoretical studies based on density functional theory calculations. This unique property can be exploited for environmental remediation, as exemplified in the effective degradation of a range of organic pollutants. Results from this study highlight the unique potential of MIH in the structural engineering of functional nanomaterials for sustainable energy technologies.