Efficient visible light-induced degradation of rhodamine B by W(NxS1-x)2 nanoflowers

Improved Photo-Excited Carriers Transportation of WS2 -O-Doped-Graphene Heterostructures for Solar Steam Generation

Two-dimensional (2D) transition metal dichalcogenides and graphene have revealed promising applications in optoelectronic and energy storage and conversion. However, there are rare reports of modifying the light-to-heat transformation via preparing their heterostructures for solar steam generation. In this work, commercial WS₂ and sucrose are utilized as precursors to produce 2D WS₂ -O-doped-graphene heterostructures (WS₂ -O-graphene) for solar water evaporation. The WS₂ -O-graphene evaporators demonstrate excellent average water evaporation rate (2.11 kg m^-2  h^-1 ) and energy efficiency (82.2%), which are 1.3- and 1.2-fold higher than WS₂ and O-doped graphene-based evaporators, respectively. Furthermore, for the real seawater with different pH values (pH 1 and 12) and rhodamine B pollutants, the WS₂ -O-graphene evaporators show great average evaporation rates (≈2.08 and 2.09 kg m^-2  h^-1 , respectively) for producing freshwater with an extremely low-grade of dye residual and nearly neutral pH values. More interestingly, due to the self-storage water ability of WS₂ -O-graphene evaporators, water evaporation can be implemented without the presence of bulk water. As a result, the evaporation rate reaches 3.23 kg m^-2  h^-1 , which is ≈1.5 times higher than the regular solar water evaporation system. This work provides a new approach for preparing 2D transition metal dichalcogenides and graphene heterostructures for efficient solar water evaporation.

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

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.