In this study, density functional theory (DFT) was employed to investigate the structural stability, electronic properties, adsorption behaviour, optical characteristics, and hydrogen evolution reaction (HER) activity of BN-doped quasi-tetragonal packed (qTP) C 60 polymeric nanosheets. Adsorption studies reveal that BN doping significantly enhances the material's affinity towards H 2 O molecules compared to CO 2 and N 2 , emphasizing the critical influence of humidity in modulating gas-sensing responses. Bader charge analysis and adsorption energy calculations further con- firm the strong interaction with H 2 O, inducing band gap modifications within the 0.5 to 1.2 eV range. Optical analysis indicates improved light absorption in the visible spectrum, reinforcing the potential of these nanosheets for optoelectronic and photocatalytic applications. Additionally, HER activity assessments demonstrate that BN doping effectively lowers the overpotential for hydrogen evolution, thereby enhancing catalytic efficiency. These findings collectively establish BN-doped qTP C 60 nanosheets as promising materials for greenhouse gas capture, humidity sensing, and sustainable energy applications, owing to their superior gas selectivity, enhanced optical properties, and improved electrocatalytic performance.