Narrow Results

Large specific surface area porous g-C₃N₄ nanosheets were prepared by utilizing acetaldehyde-mediated melamine. The synthetic processes adopted two-step thermal treatments which are in N₂ and then in an air atmosphere. The introduced acetaldehyde made melamine condensation incompletely and generated body defects in g-C₃N₄ when heated in N₂. Further heating in air realized pores formation at sites of body defects, thus increase the specific surface area of g-C₃N₄. Notably, the introduction of acetaldehyde is beneficial to generate high concentration defects, which are active sites for thermal oxidative etching, and increase the yield of g-C₃N₄ by inhibiting the sublimation of melamine. The photocatalytic performance of obtained g-C₃N₄ was evaluated by the degradation of 2-propanol under visible light irradiation ($\lambda >420$nm). The porous g-C₃N₄ exhibits excellent photocatalytic performance than bulk g-C₃N₄. The addition of trace acetaldehyde significantly increased the specific surface area and enhanced photocatalytic activity, providing a new idea for the development of simple, low-cost and high active g-C₃N₄ photocatalyst.

Density functional theory (DFT) analyses were carried out to study electronic structures and magnetic properties of Mn- and Cu-doped GaNNS. To investigate the influence of transition metal atoms (TM) on magnetic properties, we substituted Ga atoms with Mn and Cu atoms in different concentrations. Investigation shows that TM leads to electronic structural reconstruction which changes their properties in this way, and plays a significant role in spin polarization. Although the pure nanosheet is a nonmagnetic semiconductor, the doped atoms induce magnetism in the structure. The band gap changes monotonically depending on the concentration of TM atoms. The observed good half-metal ferromagnetism GaNNS:Mn, allows them to be a potential candidate for use in spintronics. The local magnetic moment calculated from Mulliken analyses for the Mn atom is approximately 4.05 $\mu$B.