Facile synthesis of Mesoporous Sm@ POA/TP and POA/TP nanocomposites with excellent performance for the photocatalytic degradation of MB and MG dyes Yahiya Kadaf Manea, Amjad Mumtaz Khan * , Syed Ashfaq Nabi Department of Chemistry, Aligarh Muslim University, Aligarh, 202002, India article info Article history: Received 29 November 2018 Accepted 5 March 2019 Available online 21 March 2019 Keywords: Nanocomposites Poly o-anisidine titanium (IV) phosphate Metal ions separation Photocatalytic degradation Optical properties abstract A highly efficient and recyclable catalysts, mesoporous poly o-anisidine titanium phosphate (POA-TP) and Sm co-doped POA-TP have been synthesized by chemical in situ polymerization in micellar media. Mesoporous nanocomposites of POA-TP and Sm@ POA-TP have been characterized by instrumental techniques such as FTIR, XRD, TGA-DTA, SEM, TEM, PL, electron-paramagnetic resonance (EPR) spec- troscopies & UVevis diffuse reflectance spectroscopy (DRS) and their photocatalytic performance were investigated based on the degradation of methylene blue (MB) and malachite green (MG) dyes. The optical properties revealed that the band gap of Sm@POA-TP was reduced from 3.76eV (POA-TP) to 3.70 eV (Sm@POA-TP) due to the presence of new donor energy levels with Sm 3þ loading. The experi- mental results indicated that the enhanced photo-catalytic performance with Sm@POA-TP could be attributed to the increased optical absorption and efficient separation and migration of photo-produced charge carriers with decreasing the recombination of electronseholes creating from doping effects. Cyclic voltammetry study was employed to investigate the redox behaviors and the current producing ability of the materials. The distribution coefficient values were used as the basis for the separation and determination of metals in water samples. The analytical column separation efficiency was explored by achieving binary separations of metal ions like Mg 2þ ePb 2þ, Mg 2þ e Fe 2þ , Sr 2þ ePb 2þ , Sr 2þ eFe 2þ , Zn 2þ ePb 2þ , Zn 2þ e Fe 2þ . This study could lead to the synthesis of low cost photocatalysts highly efficient for the removal of environmentally hazardous dyes and metal ions from aqueous solution. © 2019 Published by Elsevier B.V. 1. Introduction Heavy metals and nonbiodegradable such as organic dyes contaminate the environment causing considerable destruction of the ecosystem and irreparable loss to human health due to their high toxic and carcinogenic properties. Moreover, the colour of wastewater containing dyes can inhibit photosynthesis in aquatic plants and causes deterioration of water quality unsuitable for human consumption [1e4]. Therefore, photocatalysis is one of the promising methods that can be used to save the aquatic environ- ment by oxidizing low concentrations of organic pollutants in water. Furthermore, it is considered as photochemical reaction at semiconductor surface using sunlight as a freely available renew- able source under natural conditions. Semiconductor composites have been of great interest due to its unique quantum nature, which changes the material solid-state properties [5e7]. Con- ducting and electro-active polymers have received interest of re- searchers in order to explore their potential in various fields. The advantages of these conductive polymers having high absorption coefficients in the visible part of the spectrum, high mobility of the charge carriers (induced by extended p-conjugated electronic system) and high stability make them excellent choice for titanium based composites [8e10]. Recently, it has been observed that the incorporation of inorganic template, titanium (IV) into the matrix of the conducting polymers such as POA enhances the performance of both the ‘host’ and the ‘guest’ thereby altering physical and chemical properties of composites [11 , 12]. These composite are considered as heterogeneous disordered systems with a comple- mentary behaviour between the polymeric matrix and the inor- ganic dispersed phase [13, 14]. At present, development of composites and doped - composites with nanoporous structure are being explored widely in diverse fields such as electrode sensors, * Corresponding author. E-mail address: amjad.mt.khan@gmail.com (A.M. Khan). Contents lists available at ScienceDirect Journal of Alloys and Compounds journal homepage: http://www.elsevier.com/locate/jalcom https://doi.org/10.1016/j.jallcom.2019.03.091 0925-8388/© 2019 Published by Elsevier B.V. Journal of Alloys and Compounds 791 (2019) 1046e1062