Morphology Controllable Fabrication of Tungsten Oxide for Enhanced Photocatalytic Performance

Oxygen-deficient WO3-x spheres for electrochemical N2 oxidation to nitrate

Nitrate synthesis via the electrochemical nitrogen oxidation reaction (e-NOR) is widely recognized as a potential alternative to the energy-intensive Ostwald process. However, electrocatalysts with strong N2 adsorption and activation abilities remain largely undeveloped due to kinetic hindrances caused by the high bond energy of NN. Here we designed a hollow WO3 sphere with an optimal concentration of oxygen vacancies and studied its e-NOR performance. The optimally synthesized oxygen-deficient WO3 (WO3-x) achieved a high nitrate yield of 311.15 µmol h-1gcat.-1 and a Faraday efficiency of 2.00 %, which is probably due to the presence of a moderate amount of oxygen vacancies on the WO3-x surface and the hollow spherical structure, which further improves the accessibility of the inner active surface. Our work could potentially stimulate research into transition metal oxide-based materials for e-NOR applications.

Peroxydisulphate activated FTO-WO3 nanorods based photoelectrocatalytic degradation of tetracycline: Intermediate products, degradation pathway and ecotoxicity studies

This work reports sulphate radical assisted photoelectrocatalytic (SR-PEC) degradation of tetracycline using a visible light active fluorine-doped tin oxide - tungsten trioxide nanorods (FTO-WO3 NRs) photoanode. The WO3 NRs were synthesised via the hydrothermal method and then conducted on the FTO glass to form a photoanode. When the photoanode was applied without sulphate radicals for PEC degradation, 10 % of the tetracycline was degraded. Conversely, when 3 mM persulphate was added, the extent of tetracycline degraded was 88 % using the UV-vis spectrophotometer and 99 % using the ultra-performance liquid chromatography mass spectrometer (UPLC-MS) within 90 min at 1.5 V. The mechanism of tetracycline degradation was proposed based on the intermediate products identified using UPLC-MS and the extent of toxicity was evaluated using quantitative structure activity relationship (QSAR) analysis. Trapping experiment revealed that the photogenerated holes, sulphate radicals, and hydroxyl radicals were the oxidants that significantly took part in the degradation of tetracycline. Overall, the electrode was stable and reusable, therefore suggesting the suitability of FTO-WO3 NRs photoanode in the presence of sulphate radicals towards the decontamination of water laden with pharmaceutical pollutants.

Construction of LZU1@WO3 heterojunction photocatalysts: enhanced photocatalytic performance and mechanism insight

Our well-designed nano-WO3@LZU1 composite photocatalysts were fully characterized. Under simulated sunlight, the hybrid materials showed much higher photocatalytic activity for BBR degradation and MB degradation than WO3 or LZU1, and improved hydrogen production capacity.