  In this study, we employ a computational chemistry-based modeling approach to
investigate the adsorption mechanisms of CH$_4$ and CO$_2$ on monolayer GPNL,
with a specific focus on their effects on optical adsorption and electrical
transport properties at room temperature. To simulate the adsorption dynamics
as closely as possible to experimental conditions, we utilize the
self-consistent charge tight-binding density functional theory (SCC-DFTB).
Through semi-classical molecular dynamics (MD) simulations, we observe the
formation of H$_2$ molecules from the dissociation of CH$_4$ and the formation
of CO+O species from carbon dioxide molecules. This provides insights into the
adsorption and dispersion mechanisms of CH$_4$ and CO$_2$ on GPNL. Furthermore,
we explore the impact of molecular adsorption on optical absorption properties.
Our results demonstrate that CH$_4$ and CH$_2$ affects drastically the optical
adsorption of GPNL, while CO$_2$ does not significantly affect the optical
properties of the two-dimensional material. To analyze electron transport, we
employ the open-boundary non-equilibrium Green's function method. By studying
the conductivity of GPNL and graphene under voltage bias up to 300 mV, we gain
valuable insights into the electrical transport properties of GPNL under
optical absorption conditions. The findings from our computational modeling
approach might contribute to a deeper understanding of the potential
applications of GPNL in hydrogen production and advanced electronic devices.
