摘要
以钛酸异丙酯和富氮氮化碳(C_(3)N_(5))为原料,通过回流法制备了TiO_(2)/C_(3)N_(5)异质结光催化剂。采用XRD、FT-IR、TEM、UV-vis DRS和PL等手段详细表征了光催化剂的物相化学组成、微观形貌、光吸收响应和光生载流子分离重组。以亚甲基蓝(MB)作为目标污染物,评价了TiO_(2)/C_(3)N_(5)异质结光催化剂的活性和稳定性,基于活性基团猝灭和能带理论提出了光催化机理。结果表明,TiO_(2)和C_(3)N_(5)之间异质结的构建提升了可见光吸收响应能力,有效促进了光生载流子的分离。质量比为1∶2的TiO_(2)/C_(3)N_(5)异质结光催化剂表现出优异的光催化活性,可见光照射下MB的降解率最高达到了98.60%。循环使用5次后MB的降解率仍达到了98.30%。S型机理保留了高氧化和还原活性的空穴(h^(+))和电子(e^(-)),通过弯曲能带和内电场的构建实现了高效的电荷分离,体系中产生了大量的超氧自由基(·O_(2)^(-)),实现了MB的高效降解。
TiO_(2)/C_(3)N_(5)heterojunction photocatalyst was prepared by reflux method using isopropyl titanate and nitrogen-rich carbon nitride(C_(3)N_(5))as raw materials.XRD,FT-IR,TEM,UV-vis DRS and PL were used to characterize the photocatalyst in phase composition,chemical composition,microstructure,light-response absorption,and the separation and recombination of photogenerated carriers.Methylene blue(MB)was used as the target pollutant to evaluate the activity and stability of the TiO_(2)/C_(3)N_(5)heterojunction photocatalyst.The photocatalytic mechanism was proposed based on the free radical quenching and energy band theory.The results showed that the construction of heterojunction between TiO_(2)and C_(3)N_(5)enhanced the visible-light-response absorption ability and effectively promoted the separation of photogenerated carriers.The TiO_(2)/C_(3)N_(5)heterojunction photocatalyst with the mass ratio of 1∶2 showed excellent photocatalytic activity,and the degradation percentage of MB reached 98.60%under visible light irradiation.After 5 cycles,the degradation percentage of MB still reached 98.30%.In the S-scheme photocatalytic mechanism,the holes(h^(+))and electrons(e^(-))with high oxidation activity and reduction activity,respectively,were retained,and efficient charge separation was achieved through energy-band bending and the construction of internal electric field.Therefore,a large amount of superoxide radicals(·O_(2)^(-))were generated in the system to achieve efficient degradation of MB.
作者
胡怀生
张鹏会
Huaisheng Hu;Penghui Zhang(College of Petroleum and Chemical Engineering,Longdong University,Qingyang,Gansu 745000,China)
出处
《日用化学工业(中英文)》
北大核心
2025年第8期980-988,共9页
China Surfactant Detergent & Cosmetics
基金
庆阳市科技重大专项计划(QY-STK-2024A-140)
甘肃省自然科学基金(21JR1RM335)
庆阳市自然科学基金(QY2021A-F009)
庆阳市青年科技基金(QY-STK-2022A-014)。
