Abstract The increasing interest for addressing photocatalyst materials towards an effective application with sunlight is an important topic in materials science. We present here a novel investigation of tungsten trioxide (WO3) coatings fabricated by pulsed laser deposition (PLD) with the aim of providing a nanostructured photocatalyst capable of working with concentrated sunlight and exhibiting good stability in acidic environment. This is important since: (1) acidic pH is common in industrial wastewaters and (2) acidic pH is also known to enhance photo-Fenton reactions. Samples produced by PLD were deposited on glass slides with area of 19 cm2 and then thermally annealed at different temperatures (200, 400 and 600 °C) for 8 h to investigate the growth mechanism of WO3. Material characterization was performed by scanning electron microscopy (SEM), X-Ray diffraction (XRD) and micro-Raman, revealing the growth of a crystalline monoclinic phase of WO3 with a highly structured surface featuring nanoflakes in a flower-shape like structure with an energy bandgap of 2.6 eV. To study its photocatalytic properties, the catalyst annealed at the temperature of 600 °C evolved into a complete WO3 oxide presenting monoclinic phase and was investigated under labscale artificial visible light in both direct photocatalysis and in presence of H2O2 as a radical source (photo-Fenton-like process) using 10 ppm solutions of the Methylene Blue (MB) dye as a model pollutant. The study was then replicated in higher volume scale under concentrated solar light from a parabolic dish concentrator (PDC) apparatus to demonstrate application. Results highlighted high surface adsorption of 15%, 54% total MB degradation on direct photocatalysis and 85% in the photo-Fenton-like mode after 120 min of experiment.

中文翻译：

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纳米结构氧化钨膜的脉冲激光沉积：聚光日光修复水的催化剂

摘要 解决光催化剂材料在阳光下的有效应用越来越受到关注，这是材料科学中的一个重要课题。我们在此介绍了一项对通过脉冲激光沉积 (PLD) 制造的三氧化钨 (WO3) 涂层的新研究，旨在提供一种能够在集中阳光下工作并在酸性环境中表现出良好稳定性的纳米结构光催化剂。这很重要，因为：(1) 酸性 pH 值在工业废水中很常见，(2) 酸性 pH 值也已知会增强光芬顿反应。将 PLD 生产的样品沉积在面积为 19 cm2 的载玻片上，然后在不同温度（200、400 和 600 °C）下热退火 8 小时，以研究 WO3 的生长机制。通过扫描电子显微镜 (SEM) 进行材料表征，X 射线衍射 (XRD) 和微拉曼光谱，揭示了 WO3 晶体单斜相的生长，具有高度结构化的表面，具有花状结构的纳米薄片，能带隙为 2.6 eV。为了研究其光催化性能，该催化剂在 600 °C 的温度下退火演变成完整的 WO3 氧化物呈现单斜相，并在实验室规模的人工可见光下在直接光催化和 H2O2 作为自由基源的存在下进行研究（photo-Fenton类似过程）使用 10 ppm 亚甲蓝 (MB) 染料溶液作为模型污染物。该研究随后在来自抛物面碟形聚光器 (PDC) 设备的集中太阳光下以更高的体积规模进行复制，以演示应用。结果突出显示了 15% 的高表面吸附，