Photocatalytic degradation of Triclopyr, a persistent pesticide by ZnO/SnO 2 nano-composities Suprabha Yadav a , Naveen Kumar a,⇑ , Vijaya Kumari a , Anuj Mittal a,b , Shankar Sharma a a Department of Chemistry, Maharshi Dayanand University, Rohtak 124001, Haryana, India b Department of Chemistry, Govt. College Nahar, Rewari, India article info Article history: Received 16 July 2019 Accepted 26 July 2019 Available online xxxx Keywords: Nano-composites Persistent Triclopyr Herbicide Fungicide Hetero-junctions abstract ZnO/SnO 2 nano-composites with different compositions were synthesized by co-precipitation method and further characterized by XRD and TEM. Synthesized photocatalysts were employed for the degrada- tion of a persistent pesticide, Triclopyr (TC). Triclopyr is a well-known herbicide and fungicide. Coupled ZnO/SnO 2 photocatalysts showed better degradation of TC than the pure ZnO or SnO 2 . The nanocomposite containing the 10% of SnO 2 content (ZS-2) exhibited highest photo catalytic activity towards degradation of TC. Higher activity of the coupled oxides is attributed to the reduced recombination of photogenerated charged species due to formation of hetro-junctions between ZnO/SnO 2 . Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 1st International Conference on Manufacturing, Material Science and Engineering. 1. Introduction In recent years, both agricultural and industrial waste pollutes the water resources in the environment. Being agricultural based economy, pesticides are widely used in India. Their removal from environment is prerequisite, because of their toxic nature, chemi- cally and biologically stable characteristics and ill effect on the liv- ing organisms by entering in the body through food chain. This is a topic of concern for the global scientific community due to their highly toxic nature which causes various health hazardous issues to living organisms and ecosystems. Traditional strategies to coun- ter this problem are slow and not much effective. For better results, semiconductor assisted Advanced Oxidation Processes (AOPs) is assumed as a most promising approach for the complete mineral- ization of numerous organic wastes for environmental purification [1–5]. In recent years, various heterogeneous photocatalyst such as CuO, SnO 2 [6], Bi 2 O 3 , WO 3 [7], Fe 2 O 3 [8], ZrO 2 [9], SnS, SnS 2 , TiO 2 and ZnO were used in various environmental applications such as air and water purification, water disinfection, hazardous reme- diation etc. [10–12]. Heterogeneous oxidative photocatalysis pro- vides a potential approach for various environment related issues. Among different semiconductors ZnO having versatile nature and demarkable characteristics is widely used for the water purification; but its large band gap and high recombination rate of charge species reduces its efficacy to some extent. To conquer these drawbacks various attempts are made such as making the composites of ZnO with the other semiconductor materials, metal doping, non metal doping, codoping and modification in the sur- face properties by the addition of some additive and varying the synthesis conditions [5,13–15]. To increase the charge separation characteristics for better photocatalysis efficacy, the coupled semi- conductors with different redox energy levels were employed. These coupled semiconductors also help to increase lifespan of the charge carriers and the efficacy of the interfacial charge trans- fer to the adsorbed substrate. The mixed metal oxide not only improves physical properties but also it improves chemical as well as optical properties. Therefore instead of unitary compounds, bin- ary or ternary mixed metal oxides are considered superior one. It was observed that most of the organic pollutants, such as pesti- cides, detergents, dyes and other volatile organic compounds can be easily degraded using mixed metal oxide semiconductor nano-composites as compared to pure ones under UV as well as visible light irradiation [1–3,7]. Triclopyr, is not only used to con- trol post emergence broadleaf weeds while leaving grasses but also to control the rust diseases on crops. The natural degradation of this pesticide take a very long time and half life time period in soil is nearly 3 months. Also it remains active in vegetation decay upto nearly 3 months. Structure of triclopyr is shown below https://doi.org/10.1016/j.matpr.2019.07.746 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 1st International Conference on Manufacturing, Material Science and Engineering. ⇑ Corresponding author. E-mail address: naveenkumar.chem@mdurohtak.ac.in (N. Kumar). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: S. Yadav, N. Kumar, V. Kumari et al., Photocatalytic degradation of Triclopyr, a persistent pesticide by ZnO/SnO 2 nano-composi- ties, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.07.746