硫掺杂橄榄状BiVO_4上可见光降解亚甲基蓝和甲醛水溶液性能(英文)

Effect of sulfur doping on the photocatalytic performance of BiVO_4 under visible light illumination

在无和有S源(Na2S或硫脲)存在的条件下, 采用十二胺辅助的醇-水热法制备了多孔单斜晶相结构的BiVO4-δ和不同含量S掺杂的BiVO4-δ光催化剂. 利用多种手段表征了催化材料的物化性质, 评价了它们在可见光照射下催化降解亚甲基蓝或甲醛的反应活性. 结果表明, 所制光催化剂为单斜白钨矿晶相结构, 具有多孔橄榄状形貌, 比表面积为8.4-12.5 m2/g, 带隙能为2.40-2.48 eV.在S掺杂BiVO4 表面同时含有Bi5+, Bi4+, V5+和V4+物种. S掺杂对BiVO4-δ光催化剂的活性影响很大. 在可见光下照射下, BiVO4-δS0.08光催化剂对亚甲基蓝和甲醛降解反应显示出最高的光催化活性, 这与其较高的表面氧物种浓度和较低的带隙能相关.

Porous monoclinic bismuth vanadate（BiVO4） and sulfur‐doped bismuth vanadates（BiVO4-δS0.05,BiVO4-δS0.08,and BiVO4-δS0.12） were synthesized by a dodecylamine‐assisted alcohol‐hydrothermal route in the absence and presence of thiourea or Na2S.The physicochemical properties of the materials were characterized and their photocatalytic performance for the degradation of methylene blue and formaldehyde under visible light was evaluated.The samples have a single phase monoclinic scheetlite crystal structure with a porous olive‐like morphology,surface areas of 8.4-12.5m2/g,and bandgap energies of 2.40-2.48 eV.Surface Bi5＋,Bi3＋,V5＋,and V4＋ species were present on the S‐doped BiVO4-δ samples.Sulfur doping influenced the surface Bi5＋/Bi3＋,V5＋/V4＋,and Oads/O latt molar ratios,and the amount of sulfur doped had an important effect on the photocatalytic performance.Under visible light,BiVO4-δS0.08 performed the best in the photodegradation of methylene blue and formaldehyde.A higher surface oxygen species concentration and a lower bandgap energy were responsible for the excellent visible light photocatalytic performance of BiVO4-δS0.08.