Transition-metal-doped biphenylene for enhanced CO detection: A high-throughput first-principles study

Our study examines the CO detection capabilities of pristine biphenylene (BP) and transition-metal-doped BP (M–BPx, x = 1 or 2), a novel two-dimensional nano-carbon material. Despite BP's potential in toxic gas detection, its low CO adsorption energy (E_ads) of 0.134 eV limits its application. Utilizing a combined strategy of high-throughput computational screening and DFT technique, we accurately identified the ground state configurations of CO-adsorbed M–BPx (M = Sc, Ti, Fe, Co, Ni, and Zn) and confirmed M doping significantly boosts BP's CO adsorption ability, with E_ads values ranging from 2.809 to 8.206 eV. This improvement is supported by ab initio molecular dynamics simulations and ionic d-p bonding interactions observed in electron localization functions, densities of state (DOS), and bond population analysis. Additionally, CO adsorption induces notable DOS changes in the M–BPx systems, validating the potential of M–BPx as suitable materials for CO detection. Notably, Zn-BP2 show notable work function shift after CO adsorption (0.36 eV), outperforming pristine BP's 0.30 eV shift, and favorable recovery time (8.940 s). These shifts underscore the potential of Zn-BP2 for work function-based high-temperature CO sensor, marking it as a promising material for sensitive CO detection.