title: Understanding self-photorechargeability of WO(3) for H(2) generation without light illumination.
abstract: This work presents insight into the self-photorechargeability of WO(3), whereby the intercalation of positive alkali cations is accompanied by the simultaneous storage of photo-excited electrons. The cyclic voltammetry studies verify the photo-assisted intercalation and de-intercalation of Na(+) and K(+) from the flower structured WO(3). A storage capacity of up to 0.722 C cm(-2) can be achieved in a saturated (0.68 M) K(2)SO(4) electrolyte solution. However, the best photo recharge-discharge stability of the electrode are observed at a lower (0.1 M) cation concentration. At high electrolyte concentrations, the intercalated cations are firmly trapped, as indicated by the structural modifications observed in Raman analysis, resulting in much less photocharging and discharging abilities in subsequent cycles. The study also shows that the stored electrons can be successfully used to generate H(2) with 100 % faradaic efficiency in the absence of light.
authors: ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia.
authors: Charlene
authors: C
authors: Ng
authors: Akihide
authors: A
authors: Iwase
authors: Yun Hau
authors: YH
authors: Ng
authors: Rose
authors: R
authors: Amal
mesh_terms: D004563:Electrochemistry; D006859:Hydrogen / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D055668:Photochemical Processes; D012666:Semiconductors; D013431:Sulfates / Q000737:chemistry; D014414:Tungsten / Q000737:chemistry*
chemical_list: D010087:Oxides; D013431:Sulfates; C012036:sodium sulfate; C031512:potassium sulfate; D006859:Hydrogen; C511604:tungsten oxide; D014414:Tungsten