Bismuth Oxyhalide Induced Growth of Pt Nanoparticles within Mesoporous Alumina Films and their Use as Reusable Catalyst for Chromium(VI) Reduction

Green and efficient immobilization of catalytically active metal nanoparticles into porous supporting materials and their successful application in environmental remediation is of important scientific interest in practice. Herein, we established a new role of bismuth oxyhalides (BiOX) to produce Pt NPs inside mesoporous alumina to develop the nanocomposite film (Pt‐ BiOCl0.8Br0.2/Al2O3) using ethanol as reducing agent. Those films were applied as reusable catalysts for the reduction of highly toxic CrVI ions into CrIII by formic acid at room temperature. Different amounts of bismuth oxyhalides were loaded with alumina to generate Pt NPs and found 2 mol% BiOCl0.8Br0.2 loaded film showed optimum activity towards Pt generation and highest catalytic conversion of CrVI with the rate constant 0.177 min−1 which is very high considering any thin film as catalyst. Bismuth oxyhalides catalyzes the generation of Pt nanoparticles inside the mesoporous alumina film in an efficient green approach and the resultant nanocomposite (Pt‐BiOCl0.8Br0.2/ Al2O3) films showed very high catalytic activities towards the conversion of carcinogenic chromium(VI) into relatively non‐toxic chromium(III) in aqueous solution at room temperature. The catalyst films were reused for several cycles without any significant deterioration of their original activities.