Controlled synthesis of hierarchical BiOCl nanostructure with exposed {010} facets to yield enhanced photocatalytic performance for PMMA deterioration

In this work, we reported a facile and efficient method to prepare Bismuth-oxy-chloride (BiOCl) 3D-hierarchical nanostructure (HNs) with tunable exposed {010} facets by controlling [H+] for photocatalytic activity under visible light. Subsequently, this nanostructure with different weight percentage (5, 10, and 15wt%) was incorporated into a Polymethymethacrylate (PMMA) matrix to create degradable nanocomposites using the solution casting technique. After irradiation, SEM images confirmed that the as-synthesized flower-shaped BiOCl nanostructure aided in chain scission, side-group abstraction, and the formation of free radicals on the surface of PMMA, resulting in cracked, brittle, and broken BiOCl/PMMA nanocomposites. The observed diffractrogram from XRD revealed that the broad peaks of PMMA vanished, indicating that the deterioration of the polymer matrix. Furthermore, a 20% fall in char output and a 35% increase in crystallinity of visible light-exposed nanocomposites reduce the flame retardancy of PMMA, causing exceptional plastic deterioration. The poorer thermal resistance against thermal degradation is also reflected by the lower value of the calculated activation energy of irradiated samples. Reorganization in the macromolecular chains of PMMA into the structure after photo-irradiation exhibits a lower melting point and glass transition temperature values than shown through DSC scans. BiOCl/PMMA nanocomposites were subjected to an EPR experiment to examine the types of radicals released on the PMMA surface as a result of visible light-induced reactions. The production of carbonyl groups analyzed through FTIR reflects the better photocatalytic activity of BiOCl and is a measure of good degradation. For achieving decent results, the better dispersion of nanoparticles into a polymer matrix without aggregation is required. In this context, the stability of the photocatalyst has also been examined, and it is concluded that 10 wt% BiOCl stood better in stability, whereas beyond this aggregation inhibits photocatalytic activity.