復合鈮酸鹽的合成和光催化活性的研究

摘 要：利用光催化劑降解有機染料具有很好的應用前景，光催化材料在光催化反應中起著重要的作用，但是如何制備化學性質穩定、在可見光下具有高的催化活性的催化劑一直是人們探索的一個主題。以Ag2O、Nb2O5、Na2CO3為前驅物，經高溫固相反應法合成了具有不同Na/Ag摩爾比的(AgNbO3)1-x(NaNbO3)x 復合鈮酸鹽。采用X-射線粉末衍射(XRD)、紫外-可見漫反射譜(UV-vis DRS)等方法對樣品的結構和光譜響應特征進行了表征，以亞甲基藍的降解反應為探針考察不同Na/Ag摩爾比的(AgNbO3)1-x(NaNbO3)x復合鈮酸鹽在可見光下的光催化活性。結果表明，由高溫固相法合成出的復合鈮酸鹽的結構隨著Na/Ag摩爾比的變化而變化，光譜響應特征隨Na/Ag摩爾比的減小逐漸紅移，而對亞甲基藍的降解性能隨Na/Ag呈規律性變化，其中(AgNbO3)0.6(NaNbO3)0.4復合鈮酸鹽呈現最好的光催化活性。

關鍵詞：Ag2O；Nb2O5；復合鈮酸鹽；亞甲基藍；光催化降解

中圖分類號：TQ426文獻標識碼：A文章編號：1672-1098(2012)01-0017-05

收稿日期：2011-12-29

基金資助：國家自然科學基金面上資助項目(21071004)；安徽省自然科學基金資助項目（11040606M38）

作者簡介：孫明明（1986-），男，安徽壽縣人，在讀碩士，研究方向為環境催化及其新材料的研究。

Preparation and Photocatalytic Activities of Niobate Composites

SUN Ming-ming， WU Zheng， HE Jie

(School of Chemical Engineering， Anhui University of Science and Technology， Huainan Anhui 232001， China)

Abstract:Photocatalytic degradation by using organic dye has good prospects. The photocatalytic material plays an importan role in process of dye photocatalytic degradation， however it has been an interesting topic how to prepare photocatalytic materials with high chemical stability and excellent catalytic activity under visible light irradiation. The niobate composites ［(AgNbO3)1-x(NaNbO3)x］ were synthesized by a solid-state reaction method， and Ag2O、Nb2O5 and Na2CO3 were used as precursors. The structure and spectral response characteristics were characterized by means of powder X-ray diffraction (XRD) and ultraviolet visible diffuse reflectance spectroscopy (UV-vis DRS)， and the photocatalytic activity of the niobate composites were evaluated by degradation reaction of methylene blue under natural light. The results showed that the structure of niobate composites change with different Na / Ag molar ratio， and the spectral response existed red shift with the decreases Na / Ag molar ratio， which led to photocatalytic activity to degradation of methylene blue vary with Na/Ag ratio. It was found that (AgNbO3)0.6(NaNbO3)0.4 niobate composite showes the highest photocatalytic activity to degradation of methylene blue.

Key words:Ag2O； Nb2O5； niobate composites； methylene blue； photocatalytic degradation

隨著人們環保意識的不斷增強和對自然能源（太陽能）的充分利用，人們越來越關注可直接利用自然光的一類可見光-光敏感催化劑。雖然，可見光-光敏感催化劑已經被用來分解一些有機化合物，例如Pd／TiO2光催化劑和一些新型催化劑［1-2］。但是，一類具有高活性的可見光-光敏感催化劑仍然是有必要開發的。

對于高活性的可見光-光敏感催化劑必須滿足具有可見光吸收好和光誘發能量小這兩個條件。……