摘要
The construction of efficient photocatalysts has received much attention in wastewater treatment.In this study,Nb-doped NaTaO_(3) was prepared with different doping ratio by a facile hydrothermal method.The prepared catalysts were analyzed by X-ray diffraction,scanning electron microscopy,Brunauer-EmmettTeller(BET)theory,ultraviolet–visible diffuse reflectance spectroscopy.Then the synthesized catalysts were employed to degrade a model pollutant,methylene blue(MB),under a 250 W mercury lamp.The characterization tests confirm that Nb was successfully doped into the crystal structure of NaTaO_(3) and the modified NaNb_(x)Ta_(1)·xO_(3)(x is the doping ratio;x=0.25,0.5,0.75)samples were formed,which were in regular cubic shapes just like pure NaTaO_(3).The synthesized NaNb_(x)Ta_(1)·xO_(3)(x=0.25,0.5,0.75)had improved specific surface area and narrowed band gaps compared with pure NaTaO_(3).In photocatalytic degradation experiments,NaNb0.75Ta0.25O_(3) presented the best photocatalytic activity ascribed to the narrow band gap and the high surface area,degradating 95.7%of MB after 180 min of reaction,which was even twice the ability of pure NaTaO_(3).Besides,the effects of possible inorganic anions and cations in wastewater on photocatalytic degradation were investigated.Electron spin resonance(ESR)tests and capture experiments were also conducted and a possible photocatalytic mechanism was proposed.This work provides a direction for constructing superior NaTaO_(3)-based photocatalysts to be widely utilized in environmental protection.
基金
This work was supported by the Innovative Research Groups of the National Natural Science Foundation of China(51621005).
