Exploitation of the synergistic effect between surface and bulk defects in ultra-small N-doped titanium suboxides for enhancing photocatalytic hydrogen evolution
Exploitation of the synergistic effect between surface and bulk defects in ultra-small N-doped titanium suboxides for enhancing photocatalytic hydrogen evolution
复制标题
利用超小氮掺杂钛低氧化物表面和体缺陷之间的协同效应来增强光催化析氢
DOI：
10.1039/c8cy01717d
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发表时间：
2018
影响因子：
5
通讯作者：
xianying wang
中科院分区：
文献类型：
--
作者：
xianying wang
通过水热煅烧途径实现了具有丰富表面键的超小型氮掺杂钛低氧化物（约 10 nm）的制造。该设计概念利用表面和体缺陷的“双面”作用来设计带隙和载流子转移分离率。在制备过程中，抗坏血酸作为给电子双齿配体和还原剂，促进具有特定Ti-O-C表面键的超小纳米晶体结构的形成。尿素被用作面稳定剂和氮源，引入间隙氮缺陷。物理化学性质的综合表征清楚地表明，丰富的Ti-O-C键、适当的氮掺杂和明确的块体晶体结构有助于带隙变窄和快速的载流子分离速率。在相同条件下，与商业 P25 和锐钛矿产品相比，具有最佳晶体和电子结构的有缺陷的低氧化钛表现出更高的光催化析氢活性。还值得注意的是，所获得的产品在不使用任何贵金属助催化剂的情况下仍然可以产生光催化析氢活性。
Fabrication of ultra-small N-doped titanium suboxides (ca. 10 nm) with abundant surface bonds is realized via a hydrothermal-calcination route. The design concept takes advantage of the “double-faced” roles of surface and bulk defects in engineering the band gap and charge carrier transfer–separation rate. During the preparation process, ascorbic acid functioned as an electron-donating bidentate ligand and reducing agent, and promoted the formation of ultra-small nanocrystalline structure with specific Ti–O–C surface bonds. Urea was utilized as a facet stabilizer and nitrogen source, introducing interstitial nitrogen defects. Comprehensive characterization of the physiochemical properties clearly showed that abundant Ti–O–C bonds, proper nitrogen doping and well-defined bulk crystalline structure contribute to band gap narrowing and fast carrier separation rate. The defective titanium suboxide with optimal crystal and electronic structure exhibited much higher activity for photocatalytic hydrogen evolution compared to commercial P25 and anatase products under identical conditions. It is also noteworthy that the obtained products could still yield photocatalytic activity for H2 evolution without using any noble metal co-catalyst.