A Facile Sol-Gel Process for Synthesis of ZnWO_4 Nanopartices with Enhanced Band Gap and Study of Its Photocatalytic Activity for Degradation of Methylene Blue

摘要

ZnWO4 nanoparticles were synthesized by a facile sol-gel method using Zn(CH3COO)(2) and Na2WO4. The as-prepared ZnWO4 was characterized by several techniques: XRD, FTIR, TEM, FESEM, EDS, BET, PL and DRS. The effects of pH and calcined temperatures were investigated on the crystal structure of the ZnWO4 photocatalyst. Results showed that pure ZnWO4 was synthesized in pH 6 and calcined temperature 500 degrees C for 5h. The synthesized ZnWO4 nanoparticles have a mean diameter less than 100nm and the bond gap energy are about 3.20eV. ZnWO4 nanoparticles showed efficient photocatalytic activity for the degradation of methylene blue under ultraviolet light irradiation. The apparent rate constant (k) of photodegradation reaction was obtained as 1.62x10(-2)min(-1).