Revealing the Impact of Alkaline Agents on the Photocatalytic Characteristics of Black Titanium Dioxide (TiO<sub>2</sub>)
Muhammad Danish Khan, Masood ul Hassan Farooq, Iqra Fareed, Zulfiqar Ali, Hafiza Sadia Anum, Yahya Sandali, Muhammad Bilal Tahir, Faheem K. Butt
Abstract
Black TiO 2 owing to its fascinating photocatalytic properties has attracted research interest all around the world. Herein, the template-free hydrothermal method has been used to prepare black-TiO 2 using different alkaline reagents (NaOH, NH 4 OH, LiOH, and KOH) to study their effect on the physiochemical properties. XRD, Raman spectroscopy, FESEM, EDX, UV–vis DRS, and PL investigations were carried out and comparatively discussed. The as-prepared black TiO 2 has been subjected to photocatalytic degradation of methylene blue (MB) under visible light irradiation. Black TiO 2 prepared from NH 4 OH displayed superior MB removal compared to others. The exceptional photocatalytic performance is attributed to its smaller band gap and enhanced porosity of the material. Meanwhile, black TiO 2 prepared from KOH exhibited the least photocatalytic degradation capability due to abundant oxygen vacancies. Furthermore, the proposed mechanism highlights the effect of chemical reagents on the physiochemical properties of black TiO 2 and describes the cause of poor photocatalytic behavior of KOH-based black TiO 2 compared to others.