CAJ | 학술논문

以钛酸正丁酯、硝酸哑铈及氨水为前驱体运用溶胶-凝胶法对TiO_2进行Ce及N单一和共掺杂改性,以甲基橙光催化降解为探针考察掺杂组分对催化剂的紫外、可见光活性影响,观察到了Ce及N的单一掺杂及共掺杂催化剂紫外、可见光活性的明显提升.运用X射线衍射(XRD)、低温氮气吸附(BET)、紫外-可见漫反射吸收光谱(DRS)、程序升温氧脱附(TPD)和程序升温氧化(TPO)等表征手段从催化剂的晶体结构及形貌、比表面积、紫外及可见光响应特性、表面吸附氧量及吸附氧循环性能等方面尝试理解掺杂组分的光活性影响机制.实验结果表明掺杂改性催化剂中适量Ce组分的作用在于通过抑制催化剂的晶粒长大、团聚和锐钛结构向金红石结构的相转变,提高催化剂的光相应强度和拓展光响应范围,增加催化剂表面吸附氧容量和促进催化剂的表面氧循环,有效捕获光生载流子,衍生各类高活性自由基物种和增大催化剂比表面积等方面增进催化剂的光催化性能.
이태산정정지、초산아시급안수위전구체운용용효-응효법대TiO_2진행Ce급N단일화공참잡개성,이갑기등광최화강해위탐침고찰참잡조분대최화제적자외、가견광활성영향,관찰도료Ce급N적단일참잡급공참잡최화제자외、가견광활성적명현제승.운용X사선연사(XRD)、저온담기흡부(BET)、자외-가견만반사흡수광보(DRS)、정서승온양탈부(TPD)화정서승온양화(TPO)등표정수단종최화제적정체결구급형모、비표면적、자외급가견광향응특성、표면흡부양량급흡부양순배성능등방면상시리해참잡조분적광활성영향궤제.실험결과표명참잡개성최화제중괄량Ce조분적작용재우통과억제최화제적정립장대、단취화예태결구향금홍석결구적상전변,제고최화제적광상응강도화탁전광향응범위,증가최화제표면흡부양용량화촉진최화제적표면양순배,유효포획광생재류자,연생각류고활성자유기물충화증대최화제비표면적등방면증진최화제적광최화성능.
Ce and/or N doped TiO_2 catalysts were prepared by sol-gel process with tetrabutyl titanate, cerium nitrate and ammonia as raw materials. The photo catalytic activity of the as-prepared catalysts under both ultraviolet and visible light irradiation was evaluated by degradation of methyl orange. Significant improvement of photocatalytic activity were observed by codoping of TiO_2 with Ce and N. X-ray diffraction(XRD), low temperature N_2 adsorption (BET), UV-Vis diffuse reflectance spectroscopy (DRS), temperature programmed desorption of oxygen (TPD), temperature programmed oxidation (TPO) and transmission electron microscope (TEM) methods were employed to characterize the as-prepared photocatalysts for the elucidation of effects of crystal structure and surface morphology, specific surface area, optical characteristics and oxygen storage/release properties of doped catalyst on its photocatalytic performance. It has been shown that the role of proper amount of Ce in doped catalysts played as to enhance the thermal stability of catalyst for the suppression of growth or aggregation of crystal particles and transition of crystal phase from anantase to rutile, to promote the circulation of oxygen storage/release, and concomitantly, increase the optical absorbance, extend the light response to the visible region, suppress the recombination of charge carrier by trapping of photoinduced electrons, derive active radical species, and simultaneously, have a favorable effect on the BET surface area increase.