Controlling/living polymerization of MMA with RGO/BiVO4 as photoinitiator

In this study, reduced grapheme oxide (RGO)/BiVO₄ composite was prepared and characterized by FT-IR, XRD, and UV spectrum. Photo-chemically-mediated atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was successfully performed at 25°C in N,N-dimethylformamide (DMF) with RGO/BiVO₄ as photoinitiator, FeCl₃·6H₂O/triphenylphosphine (PPh₃) as catalyst, and ethyl 2-bromoisobutyrate as ATRP initiator. MMAs were polymerized in a controlled manner under ultraviolet (UV) light and sunlight conditions. The results show that a first-order kinetics model was obeyed up to higher conversion. The reaction gave well-controlled PMMA with M_n,GPC close to the theoretical value and a narrow MWD (M_w/M_n<1.5). The experiments of light on and off reveal the photoredox cycle between Fe(III) and Fe(II) species. The living character was further verified by the chain extension experiments.