Molecular p-n heterojunction-enhanced visible-light hydrogen evolution over a N-doped TiO2 photocatalyst
Molecular p-n heterojunction-enhanced visible-light hydrogen evolution over a N-doped TiO2 photocatalyst
复制标题
N 掺杂 TiO2 光催化剂上的分子 p-n 异质结增强可见光析氢
DOI：
10.1039/c7cy00495h
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发表时间：
2017-05-21
影响因子：
5
通讯作者：
Long, Jinlin
中科院分区：
文献类型：
--
作者：
Chen, Liming;Gu, Quan;Long, Jinlin
This study was mainly aimed at designing molecular p-n heterojunctions on the surface of N-doped TiO2 for visible-light hydrogen evolution. A series of NiO/N-TiO2 samples were prepared via NH3-postnitridation of nickel oxide-modified TiO2. H-2 production from ethanol/water solution was utilized as a model reaction to evaluate the photocatalytic properties of the catalysts. Compared to N-TiO2, a 90-fold-enhanced H-2 evolution rate was achieved over the optimal NiO/ N-TiO2 catalyst with a 0.5 wt% Ni content. Detailed characterizations clearly showed that loading NiO via wet impregnation leads to high dispersion of Ni2+ species on the surface oxygen vacancy (Vo) sites of the anatase TiO2 nanoparticles, predominantly presenting mononuclear Ti-O-Ni heteroatomic clusters on the surface of TiO2 in the case of low Ni content. These surface heteroatomic clusters can speed up the transfer and separation of photogenerated carriers of N-TiO2. It can thus be established that the molecular Ti-O-Ni heterojunctions are the main contributors to the synergistic enhancement of H-2 evolution, whereas NiO nanoclusters are not responsible for the photoactivity. Only one of the N species, N-Ti-Vo, was active and effective for this cooperation with the hydrogen-releasing Ni sites, which can induce ca. 20-fold improvement of hydrogen production over NiO/TiO2 under visible light irradiation.
