Au@g⁃C_(3)N_(4)支架的制备及其光催化性能

Preparation and Photocatalytic Performances of Au@g⁃C_(3)N_(4) Scaffold

以三聚氰胺、甲醛、尿素等原料合成具有可塑性的三聚氰胺树脂,通过发泡法构建前驱体支架,并通过磁控溅射法在支架表面沉积金,550℃下热聚合后,成功制备得到负载Au的石墨相氮化碳(Au@g⁃C_(3)N_(4))支架,其比表面积可达1480 m^(2)·g^(-1)。负载6%Au后,Au@g⁃C_(3)N_(4)支架的紫外吸收光谱在550 nm处出现了新的吸收峰,吸收带边红移至507 nm,禁带宽度缩小至2.45 eV,Au@g⁃C_(3)N_(4)支架荧光强度和阻抗显著降低,光电流从0.28μA·cm^(-2)提升至0.62μA·cm^(-2)。负载Au既拓宽了Au@g⁃C_(3)N_(4)支架可见光吸收性能,又抑制了电子-空穴对的复合,光催化性能稳定,光催化降解罗丹明B的降解率提高近1倍。此外,Au@g⁃C_(3)N_(4)支架强度适中,具有一定韧性,在光催化领域应用中便于回收和再利用。

The plastic melamine⁃formaldehyde,which was synthesized from melamine,formaldehyde,and urea,was used as the precursor for the formation of the melamine⁃formaldehyde scaffold by the microwave foaming method.Then,Au was deposited on the melamine⁃formaldehyde scaffold by the magnetron sputtering.Finally,Au deposited graphite carbon nitride(Au@g⁃C_(3)N_(4))scaffold with a specific surface area of 1480 m^(2)·g^(-1) was successfully prepared by the thermal polymerization at 550℃.After deposited 6%Au,the UV⁃Vis spectrum of Au@g⁃C_(3)N_(4) scaffold showed a new absorption peak at 550 nm,its absorption band edge was shifted to 507 nm,and its bandgap was reduced to 2.45 eV.Moreover,the fluorescence intensity and the electrochemical impedance decreased significant⁃ly,and the photocurrent increased from 0.28 to 0.62μA·cm^(-2).The deposition of Au not only widens the UV⁃Vis absorption performance of Au@g⁃C_(3)N_(4) scaffold but also inhibits the recombination of the electron⁃hole pairs.The photocatalytic performance of Au@g⁃C_(3)N_(4) scaffold was stable,and its photocatalytic degradation rate for rhodamine B was about one time higher than that of g⁃C_(3)N_(4) scaffold.Additionally,the Au@g⁃C_(3)N_(4) scaffold would be easy to recycle and be reused in the applications,because the Au@g⁃C_(3)N_(4) scaffold has suitable tensile strength and tough⁃ness.