(山東理工大學(xué) 材料科學(xué)與工程學(xué)院，淄博 255049)
摘 要: 以硫脲為S的源物質(zhì)，以鈦酸丁酯為TiO2的前驅(qū)體，采用溶膠−凝膠法制備S-TiO2光催化劑。利用XRD，XPS和FTIR等技術(shù)分析S摻雜對TiO2晶格結(jié)構(gòu)的影響，并探討元素S在TiO2晶格中的化學(xué)狀態(tài)以及所形成的化學(xué)鍵的類型。結(jié)果表明：摻雜的S以S4+進(jìn)入TiO2晶格中取代部分Ti4+，形成Ti1−xSxO2催化劑；S4+在TiO2的價(jià)帶上形成1個(gè)電子占據(jù)能級，價(jià)帶上的電子占據(jù)能級的價(jià)帶頂位主要由S3p態(tài)構(gòu)成，同時(shí)S3p也有助于形成1個(gè)由Ti3d和O2p態(tài)構(gòu)成的導(dǎo)帶，S3p態(tài)與價(jià)帶的交叉使價(jià)帶變寬，導(dǎo)致能帶變窄，從而改善TiO2的光譜響應(yīng)，使吸收邊緣擴(kuò)展到可見光的區(qū)域。對亞甲基藍(lán)的光降解實(shí)驗(yàn)結(jié)果證實(shí)硫摻雜明顯提高了光催化活性。
關(guān)鍵字: S-TiO2光催化劑；摻雜機(jī)制；化學(xué)狀態(tài)；可見光；吸收活性
（School of Materials Science and Technology, Shandong University of Technology, Zibo 255049, China）
Abstract:S-TiO2 photocatalysts, with thiourea as source substance of S and titanium tetrabutoxide (Ti(OC4H9)4 as precursor of titanium dioxide, were prepared by sol-gel method. The effects of sulfur-doping on TiO2 crystal structure, the chemical states of S atom in TiO2 crystals and the chemical bonds formed in TiO2 were analyzed by XRD, XPS and FTIR. The results show that S atom as the state of S4+ in TiO2 crystal lattices substitutes part of Ti atoms and form Ti1−xSxO2 catalyst, and S4+ forms an electron-occupied level in valence band (VB), and the electron occupies level above the VB consists of S3p states, at the same time, the S3p states contribute to the formation of a conduction band with Ti3d and O2p states, the chiasma of S3p states and the VB make VB broaden and result in energy gap narrow down, and then improve the optical response of TiO2 and extend its absorption edge into the visible-light region.
Key words: S-TiO2 photocatalyst; doping mechanism; chemical state; visible light; absorption activity
