Sampaio Maria J, Yu Zhipeng, Lopes Joana C, Tavares Pedro B, Silva Cláudia G, Liu Lifeng, Faria Joaquim L
Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465, Porto, Portugal.
Clean Energy Cluster, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre Jose Veiga, 4715-330, Braga, Portugal.
Sci Rep. 2021 Oct 29;11(1):21306. doi: 10.1038/s41598-021-99841-5.
Calcination treatments in the range of 500-900 °C of TiO synthesised by the sol-gel resulted in materials with variable physicochemical (i.e., optical, specific surface area, crystallite size and crystalline phase) and morphological properties. The photocatalytic performance of the prepared materials was evaluated in the oxygen evolution reaction (OER) following UV-LED irradiation of aqueous solutions containing iron ions as sacrificial electron acceptors. The highest activity for water oxidation was obtained with the photocatalyst thermally treated at 700 °C (TiO-700). Photocatalysts with larger anatase to rutile ratio of the crystalline phases and higher surface density of oxygen vacancies (defects) displayed the best performance in OER. The oxygen defects at the photocatalyst surface have proven to be responsible for the enhanced photoactivity, acting as important active adsorption sites for water oxidation. Seeking technological application, water oxidation was accomplished by immobilising the photocatalyst with the highest OER rate measured under the established batch conditions (TiO-700). Experiments operating under continuous mode revealed a remarkable efficiency for oxygen production, exceeding 12% of the apparent quantum efficiency (AQE) at 384 nm (UV-LED system) compared to the batch operation mode.
通过溶胶 - 凝胶法合成的TiO在500 - 900°C范围内进行煅烧处理，得到了具有可变物理化学性质（即光学、比表面积、微晶尺寸和晶相）和形态学性质的材料。在含有铁离子作为牺牲电子受体的水溶液经紫外发光二极管（UV - LED）照射后的析氧反应（OER）中，对制备材料的光催化性能进行了评估。在700°C热处理的光催化剂（TiO - 700）下获得了最高的水氧化活性。具有较大晶相锐钛矿与金红石比例以及较高氧空位（缺陷）表面密度的光催化剂在OER中表现出最佳性能。已证明光催化剂表面的氧缺陷是增强光活性的原因，作为水氧化的重要活性吸附位点。为寻求技术应用，通过固定在所建立的间歇条件下测量的具有最高OER速率的光催化剂（TiO - 700）来实现水氧化。与间歇操作模式相比，连续模式下的实验显示出显著的产氧效率，在384nm（UV - LED系统）下超过12%的表观量子效率（AQE）。
