Carbon Quantum Dots sensitized Vertical WO₃ Nanoplates with Enhanced Photoelectrochemical Properties

WO₃ nanoplates (WO₃NP) sensitizing with carbon quantum dots (CQDs) photoanode was successfully fabricated by simple hydrothermal and immersing process under mild temperature. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM, Raman spectrometer and ultraviolet visible spectrometry (UV-vis). The WO₃ photoanode after CQDs loading exhibited an enhanced photocurrent density of ∼1.18 mA cm⁻² at 1.23 V vs RHE, compared to 0.96 mA cm⁻² of pristine WO₃ under simulated solar light illumination. Moreover, the modified WO₃ nanoplates with CQDs show a superior ability to capture visible light, resulting in more than 1.6 folds of photocurrent density enhancement. Meanwhile, a lower onset potential can be obtained after sensitizing, which is caused by the change of band energy positions. Notably, this efficient sensitization of CQDs could introduce a promising route to improve the light harvesting and efficiency of photoelectrochemical properties for WO₃ based photoanode.