Near infrared-light responsive WS2 microengines with high-performance electro- and photo-catalytic activities

Abstract

Tungsten disulfide (WS₂)-based micromotors with enhanced electrochemical and photo-catalytic activities are synthesized using a greatly simplified electrochemical deposition protocol at room temperature involving exclusively tungstic acid and sulfate as metal and sulfur sources without further building chemistry. The WS₂-based micromotors exhibit dual electrochemical and photo-catalytic behavior in the inner and outer layers, respectively, due to the combination of the unique properties of the sp² hybridized WS₂ outer layer with highly reactive WS₂-induced inner catalytic layers, accounting for this material's exclusive enhanced performances. A rough inner Pt–Ni layer allows tailoring the micromotor propulsion, with a speed increase of up to 1.6 times after external control of the micromotor with a magnetic field due to enhanced fuel accessibility. Such a coupling of the attractive capabilities of WS₂ with enhanced micromotor movement holds considerable promise to address the growing energy crisis and environmental pollution concerns.