Synthesis of TiO2 modified self-assembled honeycomb ZnO/SnO2 nanocomposites for exceptional photocatalytic degradation of 2,4-dichlorophenol and bisphenol A

• Published in: The Science of the total environment Vol. 746; p. 141291
• Main Authors: Ali, Wajid, Ullah, Hameed, Zada, Amir, Muhammad, Wisal, Ali, Sharafat, Shaheen, Shabana, Alamgir, Muhammad Khalid, Ansar, Muhammad Zaka, Khan, Zaheen Ullah, Bilal, Hazrat, Yap, Pow-Seng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2020
• Subjects: Calcination; Honeycomb structure; Improved charge separation; Ternary heterojunction; TiO2 modification; Ternary heterojunction; Calcination; Honeycomb structure; TiO2 modification; Improved charge separation
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.141291

In this study, we have successfully synthesized honeycomb-like self-assembled structure of TiO2 modified ZnO/SnO2 nanostructure via co-precipitation method with exceptional high degradation activities for 2,4-dichlorophenol (2,4-DCP) and bisphenol A (BPA) pollutants. The as-prepared samples were calcined in tube furnace at high elevated temperature (700, 800 and 900 °C) for 1 h. Among the TiO2 modified samples, ZST10-700 showed higher charge separation as demonstrated from surface photovoltage spectroscopy, photoluminance and electrochemical curve. Surface morphology, crystallinity, optical property and different functional groups in the samples were determined with SEM, EDX, XRD, UV–Vis DRS and FTIR, respectively. Interestingly, 72% and 58% photocatalytic degradation efficiencies were achieved with optimized ZST10-700 for 2,4-DCP and BPA, respectively. In comparison, the pure ZS-700 only showed 36% and 29% photocatalytic degradation efficiencies, respectively. The improved photocatalytic degradation efficiencies of the optimized ZST10-700 are mainly due to improved charge separation and prolonged charge lifetime. It was further verified that by increasing calcination temperature, the photocatalytic activity decreased, and this is attributed to the formation of photo-inactive phases like Zn2SnO4 and ZnTiO3. We believe that this work will provide an effective strategy to construct ternary heterojunction for the elimination of pollutants.
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•TiO2 modified ZnO/SnO2 honeycomb nanostructures were synthesized by co-precipitation method.•The binary and ternary nanocomposites exhibit higher photocatalytic activities for 2,4-DCP and BPA degradation.•The high photocatalytic activities are attributed to higher charges separation due to honeycomb self-assembled structure.•The main active species involved in the degradation were superoxide radical (•O2-) and holes (h+).