Vertically aligned interlocked tungsten oxide nanosheet thin film for photocatalytic application: effect of deposition cycles

In this work, vertically aligned interlocked tungsten oxide (WO₃) nanosheets are deposited on non-conducting substrates using the modified chemical solution deposition (MCSD) method. The number of deposition cycles is varied to tune the physicochemical properties of WO₃ thin films. The WO₃ thin films exhibit an orthorhombic crystal structure with a preferred orientation along the (111) plane. The WO₃ thin film shows the vertically aligned interlocked nanosheet morphology with a change in the lateral dimensions upon varying the number of deposition cycles. All the WO₃ thin films exhibited strong visible light harvesting characteristics in the 510–530 nm wavelength range. The WO₃ thin films are used for the visible-light-active photocatalytic degradation of organic molecules such as methylene blue (MB), rhodamine B (Rh B) and tetracycline hydrochloride (TC). The optimized WO₃ thin film shows maximum photocatalytic degradation performance of 92, 89 and 87% in 210 min for MB, Rh B and TC, respectively. The present study illustrates the usefulness of the MCSD approach for depositing vertically aligned interlocked WO₃ nanosheet thin films and enhancing photocatalytic performance.