Synthesis of fluorescent diblock copolymer nanoparticle supported catalyst for the reduction of Cr(VI), p-nitrophenol and rhodamine 6G dye: a comparative study

Abstract

A fluorescent diblock copolymer nanocomposite (DBCNC) was synthesized by ring opening polymerization (ROP) method using rhodamine 6G (R6G) dye as an initiator through bulk polymerization technique. ROP of caprolactone was carried out at $$160^{\circ } \hbox {C}$$ for 2 h under nitrogen atmosphere in the presence of stannous octoate (Sn(Oct) $$_{2}$$ ) as a catalyst followed by the ROP of tetrahydrofuran in the presence of phthalicanhydride as a co-monomer. Thus, synthesized fluorescent DBCNC was characterized by various analytical tools such as FTIR spectroscopy, UV–visible spectroscopy fluorescence emission spectroscopy, DSC, TGA and FESEM. The catalytic reduction of p-nitrophenol (NiP), Cr(VI) and R6G was carried out in the presence of DBCNC as a catalyst with the help of UV–visible spectrophotometer. The apparent rate constant ( $$k_{\mathrm{app}}$$ ) and induction time ( $$T_{\mathrm{i}}$$ ) were determined from the UV–visible spectral data. The nanosized $$\hbox {V}_{2} \hbox {O}_{5}$$ was prepared by a simple chemical reduction of bulk-sized $$\hbox {V}_{2}\hbox {O}_{5}$$ by using sodium borohydride ( $$\hbox {NaBH}_{4}$$ ) as a reducing agent. During the DBC formation, 0.01 g of nanosized $$\hbox {V}_{2}\hbox {O}_{5}$$ was added. This type of polymer supports the catalyst which is very much useful in the catalysis industry because of its easy separation and recyclable property.