title: Harvesting, storing and utilising solar energy using MoO3 : modulating structural distortion through pH adjustment.
abstract: Nanostructured molybdenum oxide (α-MoO3 ) thin film photoelectrodes were synthesised by anodisation. Upon band gap-excitation by light illumination, α-MoO3 is able to store a portion of the excited charges in its layered structure with the simultaneous intercalation of alkali cations. The stored electrons can be discharged from α-MoO3 for utilisation under dark conditions, and α-MoO3 is able to recharge itself with successive illuminations to behave as a 'self-photo-rechargeable' alkali-ion battery. The alteration of the anodisation pH allowed the crystal structure and oxygen vacancy concentrations of α-MoO3 to be modulated to achieve (i) a distorted MoO6 octahedra for enhanced charge separation and storage, (ii) a layered structure with a greater exposed (010) crystal face for rich and reversible ion intercalation and (iii) a highly crystalline thin film that suppresses electron-hole pair recombination. Overall, the larger MoO6 octahedral distortion in α-MoO3 at a higher pH favours charge storage, whereas smaller octahedral distortion at a lower pH leads to anodic photocurrent enhancement.
authors.affiliation: Particles and Catalysis Research Group (PARTCAT), School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052 (Australia).
authors.forename: Shi Nee
authors.initials: SN
authors.lastname: Lou
authors.forename: Yun Hau
authors.initials: YH
authors.lastname: Ng
authors.forename: Charlene
authors.initials: C
authors.lastname: Ng
authors.forename: Jason
authors.initials: J
authors.lastname: Scott
authors.forename: Rose
authors.initials: R
authors.lastname: Amal
mesh_terms: D011211:Electric Power Supplies; D004563:Electrochemistry; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D008968:Molecular Conformation; D008982:Molybdenum / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D012993:Solar Energy
chemical_list: D010087:Oxides; C082290:molybdenum trioxide; D008982:Molybdenum
keywords: electrochemistry; energy conversion; intercalations; molybdenum; thin films