Photocatalytic degradation of Methyl Orange using palygorskite-In2O3/In2S3 composite
Palygorskite(PGS)supported In2O3/In2S3 composites(PGS-In2O3/In2S3)were prepared from hydrothermal reaction of In2O3,thioacetamide and PGS,characterized by XRD,SEM,TEM,BET and UV-Vis DSR,and evaluated for its electrochemical impedance spectroscopy(EIS).The photocatalytic performance,ion interference resistance and cycling performance of PGS-In2O3/In2S3 with different acid-PGS mass fractions(based on the total mass of acid-PGS and In2O3,the same below)were studied in Methyl Orange(MO)degradation.The results indicated that PGS-In2O3/In2S3 exhibited a structure with the agaric-like nanosheets of In2S3 and needle-like palygorskite attaching to the surface of particles In2O3,and showed stronger light absorption in the range of 200~580 nm.50%PGS-In2O3/In2S3 composite with acid-PGS mass fraction of 50%displayed the highest photocatalytic activity in MO degradation,and MO with a mass concentration of 20 mg/L showed a degradation rate of 98.8%photocatalyzed by 20 mg 50%PGS-In2O3/In2S3 for 30 min under visible light,with the main active species involved attributed to superoxide radical and hole while the common ions such as Na+and Cl-,except H2PO4-,showing no effect.Moreover,50%PGS-In2O3/In2S3 showed better physical adsorption and photocatalytic degradation for various dyes including Malachite Green,Rhodamine B,Crystal Violet and Methylene Blue.The internal electric field between PGS and In2O3/In2S3 reduced the recombination rate of In2O3/In2S3 photogenerated carriers.