Contents lists available at ScienceDirect Ecotoxicology and Environmental Safety journal homepage: www.elsevier.com/locate/ecoenv Advanced catalytic performance of amorphous MoS 2 for degradation/ reduction of organic pollutants in both individual and simultaneous fashion ☆ Namrata Saha, Arpita Sarkar, Abhisek Brata Ghosh, Papri Mondal, Jit Satra, Bibhutosh Adhikary ⁎ Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, West Bengal, India ARTICLE INFO Keywords: Amorphous MoS 2 MPs Dye/dye mixture Degradation Mott-schotky Heterogeneous catalyst ABSTRACT A cluster [(S 2 ) 2 Mo(S 2 ) 2 Mo(S 2 ) 2 ], has been used to synthesise molybdenum sulfide microparticles (MPs) by solvothermal treatments under inert environment. During synthesis, surfactants i.e. oleylamine and dodecanthiol take part in chief role in shaping the morphology of MPs into ultrathin nano-fibre, and nano-rod. MPs have been characterized by X-ray diffraction analysis, energy dispersive X-ray spectroscopy, transmission electron micro- scopy and UV-vis spectroscopic techniques. The optical spectral data reveals a simultaneous presence of direct and indirect band gap in both MoS 2 . The material emerges as an effective catalyst towards the mineralization of different cationic dyes (rhodamine B and methylene blue) and anionic dye (rosebngal). These MPs have also been effectively used for the simultaneous degradations of different dyes in the same reaction mixture which make further highlighted the catalytic performances of MoS 2 . The above kinetics of the decomposition processes were examined and found to follow the pseudo-first-order reaction model. The plausible mechanism has been explained by comparing the position of conduction band levels of MoS 2 (measured by Mott-schotky and touc's plot) and potential value of borohydride. We have also investigated the active species behind the degradation of dyes by using different scavengers. The new catalyst was also effective for the degradation of mixture of dyes to the same extent as it was in case of individual. 1. Introduction Now a day, the degradation of individuals/ simultaneous catalytic degradation of industrial pollutants like cationic/anionic dyes are highly demanding. Although the reports on the singular degradation of these toxins by various NPs are very common but the simultaneous reduction/ degradation of mixture of different dyes are very rare (Wetchakun et al., 2012; Li et al., 2012). Due to the collective presence of different pollutants in industrial effluents together, the removal or degradation one by one is time consuming as well as very costly. To overcome this problem, industries demand the designing of different multipurpose catalysts which are capable of catalyzing the degradation of different types of toxins such as cationic and anionic dyes simulta- neously with significant rate. In the recent past, a huge number of studies have been focused on the production of nano-sized inorganic materials as they possess ver- satile of physical and chemical activity (Sardar and Rao, 2004; Rao et al., 2003; Hu et al., 1999). Of these materials, the transition metal chalcogenides are one of most useful class of semiconductor because of their significant properties in various fields (Dietl, 2002; Wood, 1988; Chang et al., 2012; Huynh et al., 2002; Mitzi et al., 2008; Schoning and Kloock, 2007; Dutta et al., 2012a; Maji et al., 2012a, 2012b; Tang et al., 2014; Dutta et al., 2012b; Dutta et al., 2014). Among these, as a sig- nificant candidate, MoS 2 emerge as it has potential applications in numerous areas as catalysts (Chen et al., 2002), electrode materials for Mg 2+ ion and Li + ion batteries (Li and Li, 2004; Wang and Li, 2007), potential hydrogen storage media (Chen et al., 2001), superconductors (Ye et al., 2014, 2012), solid super lubricants (Rapoport et al., 1997; Chen et al., 2002) and photo-electrochemical solar cells (Tributsch and Bennett, 1997; Laursen et al., 2012). Therefore a sincere effort has being given for the synthesis of amorphous MoS 2 (Saha et al., 2015) via cost-effective and eco-friendly routes as it holds a high catalytic activity because of its large concentration of lattice defects and high surface area (in amorphous structure). In addition, the disintegration of a single-source precursor (SSP) method is useful over all thermo-solution based synthetic plans since it helps to get a precise control over the MPs of pure phase selectivity, single crystallinity, definite stoichiometry and monodispersity. Vittal and co-workers has made an extension (Ng et al., https://doi.org/10.1016/j.ecoenv.2018.05.023 Received 15 January 2018; Received in revised form 11 May 2018; Accepted 11 May 2018 ☆ These authors contributed equally. ⁎ Corresponding author. E-mail address: bibhutoshadhikary@yahoo.in (B. Adhikary). Ecotoxicology and Environmental Safety 160 (2018) 290–300 0147-6513/ © 2018 Elsevier Inc. All rights reserved. T