Herein, we report the fabrication of titanium dioxide nanotubes via anodization technique through with and without hydrofluoric acid . The impact of hydrofluoric acid followed by annealing effect on TiO2 nanotubes for the solar water splitting performance was examined. Prepared TiO2 samples exhibited a diameter of about 50 to 100 nm sized nanotubes and hierarchical structures and they subjected to annealing. Synthesis and annealing effects on chemical, physical and photoelectrochemical water splitting activity of TiO2 samples were scrutinized. The crystalline nature, structure and surface morphologies of prepared TiO2 photocatalysts were explored by X-ray diffraction, scanning electron microscope, and the oxidation states of both titanium and oxygen was determined by X-ray photoelectron spectroscopy. As a consequence, after annealing at 500 ºC, TiO2 thin films treated with hydrofluoric acid solution (HF-TiO2) were found to exhibit a remarkable photoelectrochemical performance than bare TiO2 nanotubes under UV light irradiation. Moreover, the mechanistic insights acquired in the current research would be beneficial to design a novel and highly efficient photocatalyst for solar water splitting systems.

This paper presents the first report of the excellent oxygen reduction activity and durability of a composite structure that consists of highly active V2O5-WO3 electrocatalyst. Outstanding electrocatalytic performance toward oxygen reduction under alkaline medium was achieved by selecting a highly active and optimum concentration of V2O5 on WO3 composite. In particular, the excellent catalytic activity of the 25 wt.% V2O5 with 75 wt.% WO3(WV[Formula: see text] catalyst for oxygen reduction reaction (ORR) can be attributed to the optimum concentration of V2O5, high surface area, high conductivity, and mesoporous nature, since they aid facile electrochemical activity and reduced overpotential and small Tafel values than other catalysts. In addition, it exhibits long-term durability.

Abstract:Using the method of few-body physics, the solutions of ground state and some low-lying excited states [such as 1s -1s , 1s -1p and 1s -1d ]

For the commercialization of alkaline fuel cells and metal air batteries, the advances in non-precious, cheap, stable electrocatalysts for the oxygen reduction reaction (ORR) and highly active remain a major problem. To overcome this problem, a facile approach was established to fabricate non-precious metal electrocatalysts, such as nanoparticles, pristine V2O5 and their WO3 hybrids. This is the first study reporting the utilization of monoclinic-WO3-nanocrystal-coupled V2O5 that serves as ORR catalysts. Compared with 50 wt.% WO3 with 50 wt.% V2O5 (VW-2) spheres and pristine V2O5, the hybrid catalyst of 25 wt.% WO3 and 75 wt.% V2O5 (VW-1) spheres exhibits outstanding catalytic activity towards ORR. In addition, the hybrid of 25 wt.% WO3 and 75 wt.% V2O5 (VW-1) exhibits a higher long-term durability and catalytic activity than high-quality commercial Pt/C catalysts, which renders the composites of WO3/V2O5 composites hybrid a high-capacity candidate for non-precious, high-performance, metal-based electrocatalysts having high efficiency and low cost for electrochemical energy conversion. The enhanced activity of WO3/V2O5 composites is mainly obtained from the improved structural openness in the V2O5 tunnel structure when coupled with WO3.

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