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Polybrominated diphenyl ethers (PBDEs), previously incorporated in a wide variety of common products, can now be found throughout the environment. Because of their environmental persistence and the potential health hazards they pose to humans and wildlife, they have been added to the Stockholm Convention on Persistent Organic Pollutants, and they continue to be of significant concern. We report herein the first application of a nanocomposite catalyst consisting of a m -BiVO 4 /BiOBr heterojunction surface-decorated with Pd nanoparticles in the photocatalytic reductive debromination of PBDEs using visible light. Specifically, this system demonstrated both rapid and complete debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47), with an exceedingly large initial pseudo-first-order rate constant of 1.33 min −1 . Analysis of the reaction mechanism identified the stepwise degradation pathway to generate the final diphenyl ether product as well as the role of the alcohol-based sacrificial reagent. Such information provides routes towards new approaches for environmental remediation by identifying reaction pathways for common organic pollutants that remain challenging to degrade via sustainable methods. 

Bimetallic nanoparticles remain a promising avenue to achieve highly reactive catalysts. In this contribution, we demonstrate the use of a photoswitchable peptide for the production of PdAu bimetallic nanoparticles at a variety of Pd : Au ratios. Using this peptide, the biomolecular overlayer structure can be switched between two different conformations ( cis vs. trans ) via light irradiation, thus accessing two different surface structures. The composition and arrangement of the materials was fully characterized, including atomic-level analyses, after which the reactivity of the bimetallic materials was explored using the reduction of 4-nitrophenol as a model system. Using these materials, it was demonstrated that the reactivity was maximized for the particles prepared at a Pd : Au ratio of 1 : 3 and with the peptide in the cis conformation. Such results present routes to a new generation of catalysts that could be remotely activated for on/off reactivity as a function of the ligand overlayer conformation.