TiO2 Decorated Sand Grains for Photodegradation of Pollutants: Methylene Blue and Ciprofloxacin Study

This study shows a preparation and evaluation of a new non-expensive TiO2 based photocatalyst built over sand grains surfaces as an alternative green technology for water treatment. The semiconductor covalently bonded to the silica sand grains (sand@TiO2) prepared by hydrolysis of isopropoxide orthotitane over sand grains, showed a high surface area 296 m2 g-1 and a high reaction rate for methylene blue (MB) photodegradation (0.064 min-1), on steady state condition by using 3 g of sand@TiO2 and an MB solution (20 mL, 3 × 10-5 mol L-1) or ciprofloxacin hydrochloride (CIP) solution (20 mL, 1.9 × 10-3 mol L-1). Under UV irradiation with a medium pressure Hg lamp, the total MB removal reached 70% after 7 min and 45% for CIP in 60 min. Further, the photocatalyst showed to be a promising reusable material for removal of ciprofloxacin hydrochloride antibiotic (CIP) on wastewater. This new material appears as a new promising low cost and low impact reusable catalyst for water treatment.本研究报道了一种负载于石英砂粒表面的新型低成本二氧化钛（TiO₂）基光催化剂的制备与性能评估，旨在作为一种替代型绿色水处理技术。该半导体通过在砂粒表面水解原钛酸四异丙酯制得，与砂粒共价键合得到sand@TiO₂材料，其比表面积高达296 m²·g⁻¹；在稳态条件下，当使用3 g sand@TiO₂处理20 mL浓度为3×10⁻⁵ mol·L⁻¹的亚甲基蓝（MB）溶液，或20 mL浓度为1.9×10⁻³ mol·L⁻¹的盐酸环丙沙星（CIP）溶液时，展现出优异的光降解反应速率（0.064 min⁻¹）。采用中压汞灯进行紫外辐照时，7分钟内可实现70%的MB去除率，60分钟内可实现45%的CIP去除率。进一步研究表明，该光催化剂具备良好的重复使用性能，可用于废水中盐酸环丙沙星类抗生素的去除。综上，这种新型低成本、低环境影响的可重复使用光催化剂，有望成为极具应用前景的水处理材料。