Efficient dye-sensitized solar cells based on surfactant-mediated TiO2 nanostructures

Sol-gel synthesis of TiO2 on Co3O4-coated sporopollenin exine microcapsules (SECs) and photocatalytic performance of new semiconductor heterojunction material

In this study, a new approach was developed to prepare mesoporous hybrid TiO₂/Co₃O₄ coated on Juglans sporopollenin exine microcapsules (SECs). TiO₂ was synthesized on Co₃O₄-coated SECs used as substrate, by sol-gel method. The obtained semiconductor/semiconductor hetero-junction hybrid materials were characterized with X-ray diffractometry (XRD), UV-Vis absorption spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), particle size distribution, specific surface area, and zeta potential measurements. Photocatalytic performances of hybrid materials were tested for Reactive Black 5 dye under both UV and visible light. Equilibrium pH of the solution containing 10 mg/L Reactive Black 5 dye and 0.1% wt/v TiO₂/Co₃O₄ was around 4.7. After irradiation in the solar box, more than 98% of the Reactive Black 5 was photocatalytically degraded within 60 min.

A review on TiO2/SnO2 heterostructures as a photocatalyst for the degradation of dyes and organic pollutants

Industrialization, civilization and human activities have all grown steadily in recent years. As a result, small and large industries discharge many organic pollutants into the environment and contribute to environmental pollution. These compounds are quite stable and challenging to break down over time, posing a long-term risk. The heterogeneous advanced oxidation processes technology has gained tremendous attention. It depends on the light-induced formation of e^-/h⁺ pairs, which combine with water and aqueous oxygen to generate highly reactive hydroxyl radicals that degrade the organic pollutants in a solution and convert them ultimately into non-toxic products. In this paper, the synergetic impact of TiO₂-SnO₂ coupling with other semiconductor materials and their photodegradation performance on toxic contaminants in an aqueous medium has been reviewed. In addition, multiple approaches for the synthesis of TiO₂-SnO₂ photocatalysts have been discussed. Among them, hydrothermal, sol-gel, electrospinning, precipitation and even their combination are extensively used to synthesize various forms of nanostructures. These techniques demonstrate better tunability for visible absorption, suppression of e^-/h⁺ pair recombination and enhanced e^-/h⁺ separation to improve photocatalytic performance. This paper also summarises the role of different operating factors such as catalyst loading, pH, pollutants variation concentration, various light sources and oxidizing agents on the photodegradation of organic pollutants.