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In this work, WO3 nanostructures were synthesized with different complexing agents (0.05 M H2O2 and 0.1 M citric acid) and annealing conditions (400 °C, 500 °C and 600 °C) to obtain optimal WO3 nanostructures to use them as a photoanode in the photoelectrochemical (PEC) degradation of an endocrine disruptor chemical. These nanostructures were studied morphologically by a field emission scanning electron microscope. X-ray photoelectron spectroscopy was performed to provide information of the electronic states of the nanostructures. The crystallinity of the samples was observed by a confocal Raman laser microscope and X-ray diffraction. Furthermore, photoelectrochemical measurements (photostability, photoelectrochemical impedance spectroscopy, Mott–Schottky and water-splitting test) were also performed using a solar simulator with AM 1.5 conditions at 100 mW·cm−2. Once the optimal nanostructure was obtained (citric acid 0.01 M at an annealing temperature of 600 °C), the PEC degradation of methylparaben (CO 10 ppm) was carried out. It was followed by ultra-high-performance liquid chromatography and mass spectrometry, which allowed to obtain the concentration of the contaminant during degradation and the identification of degradation intermediates. The optimized nanostructure was proved to be an efficient photocatalyst since the degradation of methylparaben was performed in less than 4 h and the kinetic coefficient of degradation was 0.02 min−1.

An appropriate morphological and structure matrix configuration where lithium ions could insert and de‐insert is essential for lithium‐ion batteries (LiB). Tungsten oxides (WO3) are especially attractive materials for this aim. In this research, the effects of the morphology and composition of WO3 nanostructures on the charge/discharge behavior for Li‐ion batteries are methodically examined. On the one hand, nanostructured WO3 thin film was effectively synthesized by an electrochemical procedure. Then, an annealing treatment at 600°C in air environment for 4 h was carried out. In the second electrode synthesized, a carbon layer was uniformly deposited on WO3 nanostructures to obtain a WO3/C electrode. Finally, WO3/WS2 electrodes were prepared by means of in situ sulfurization of WO3 one‐step solid‐state synthesis using tungsten trioxide (WO3) and thiourea as precursor material. By using X‐ray photoelectron spectroscopy, X‐ray diffraction analysis, transmission electron microscopy, Raman spectra, and field‐emission scanning electron microscopy, the three electrodes have been morphologically characterized. Electrochemical properties were analyzed by cyclic voltammogram, galvanostatic charge/discharge cycling, and electrochemical impedance spectroscopy. Among all the synthesized samples, WO3/C nanostructures reveal the best performance as they exhibit the greatest discharge capacity and cycle performance (820 mA h g−1).

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