Solar Assisted Mitigation\nof Chloramphenicol and H<sub>2</sub> Evolution Using CuNi Alloy Nanoparticles on h‑BN Doped g‑C<sub>3</sub>N<sub>4</sub>: A Comprehensive Approach Combining Synchrotron\nand DFT Analysis

A simple one-step deposition–precipitation method\nwas used\nto synthesize highly active and well-defined CuNi alloy bimetallic\nnanoparticles supported on h-BN/g-C<sub>3</sub>N<sub>4</sub>. The\nnanocomposite was applied for hydrogen gas evolution via seawater\nsplitting and photocatalytic chloramphenicol (CHP) removal. Through\nTEM and synchrotron studies, the formation of CuNi alloy and uniform\ndistribution of CuNi bimetallic nanoparticles on the h-BN/g-C<sub>3</sub>N<sub>4</sub> surface was observed. The EXAFS analysis verified\nthe successful formation of the alloy, while the XPS and XANES spectra\nshowed that the bimetallic nanoparticles are in a metallic state.\nAdditionally, XANES revealed nanoparticle distortion upon interaction\nwith the support, confirming the effective formation of the nanocomposite.\nThe nanocomposite achieved a maximum hydrogen evolution rate of 3658.9\nμmol g<sup>–1</sup> h<sup>–1</sup> for 5 wt %\nCuNi(3:1)/h-BN/g-C<sub>3</sub>N<sub>4</sub>, outperforming CuNi(3:1)\nnanoparticles and pristine g-C<sub>3</sub>N<sub>4</sub> by 1.82 and\n4.31 times, respectively. Additionally, it degraded chloramphenicol\nwith a rate constant (<i>k</i><sub>app</sub>) of 0.018 min<sup>–1</sup>. Optical and electrochemical analysis revealed enhanced\ncharge mobility, extended lifetime, improved photostability, and superior\nphotoresponse. X-ray absorption spectroscopy (XAS) and density functional\ntheory (DFT) calculations attributed the performance to the synergy\nbetween the bimetallic nanoparticles and the h-BN/g-C<sub>3</sub>N<sub>4</sub> sheet. DFT calculations demonstrated the effective breakdown\nof chloramphenicol and the promotion of hydrogen gas evolution, aligning\nwith experimental observations. Cytotoxicity of CHP post-treatment\nwas analyzed using Drosophila melanogaster (fruit fly) and the Oregon-R strain of D. melanogaster.