Aluminum-doped strontium titanate SrTiO 3 (Al), has been demonstrated as the suitable photocatalyst for overall water splitting. Noble metals, such as RhCrO x , are widely applied to accelerate the photocatalytic hydrogen evolution . Herein, Ni single atoms anchored on nitrogen-doped graphene (Ni SA-NG) are adopted to replace noble metal as hydrogen (H 2 ) evolution cocatalysts for SrTiO 3 (Al)/CoO x photocatalyst. The prepared Ni SA-NG/SrTiO 3 (Al)/CoO x photocatalyst exhibits remarkable activity for photocatalytic overall water splitting with the H 2 evolution rate of 498 μmol g −1 h −1 and oxygen (O 2 ) evolution rate of 230 μmol g −1 h −1 , respectively. Ni SA-NG not only improves the efficiency of photogenerated charge transfer and separation through the Ti–O–C bonds acting as the electron transfer freeway, but also provides highly active sites to accelerate the surface H 2 evolution rate. This research provides a valuable method to construct SrTiO 3 -based photocatalyst without noble metal cocatalysts.
Aluminium doped strontium titanate, SrTiO3(Al), is considered as the most promising candidate photocatalyst for water splitting; however, it suffers from fast recombination of photogenerated charges and little photocatalytic activity for overall water splitting. Precious metals, such as RhCrOx, are always needed as cocatalysts to enhance the photocatalytic performance. Herein, nitrogen doped graphene quantum dots (NGQDs) were prepared and applied as a hydrogen evolution reaction (HER) cocatalyst of SrTiO3(Al)/CoOx for photocatalytic overall water splitting. The designed NGQDs/SrTiO3(Al)/CoOx is highly active for overall water splitting achieving a H2 evolution rate of 18.8 μmol h−1 and an O2 evolution rate of 9.0 μmol h−1, respectively. The NGQDs and CoOx are dispersed on the different crystal facets of octagonal SrTiO3(Al), which is beneficial to the spatial separation of photogenerated electrons and holes. The strong interaction between NGQDs and SrTiO3(Al) via Ti–O–C chemical bonds enhances the charge transfer and separation. Moreover, the pyrrole N species within NGQD networks act as active sites for the hydrogen evolution reaction.
Shangchun Lv,Mengxi Pei,Yuxiang Liu,Zhichun Si,Xiaodong Wu,Rui Ran,Duan Weng,Feiyu Kang
Hydrogen production from overall water splitting using SrTiO3(Al)-based semiconductors is one of the most promising routes to address energy and environmental concerns. Noble metals are needed to accelerate water splitting by promoting the charge transfer and providing active sites. However, noble metal-based catalysts have high prices and rare resources. Herein, we demonstrate a strategy to construct highly active CoxP/SrTiO3(Al) for overall water splitting. Hydrothermal method followed by an ultrasonic process was applied to prepare CoxP dots, which were loaded on the whole surface of SrTiO3(Al) as bifunctional cocatalysts. Interestingly, the CoxP dots on the (110) planes of SrTiO3(Al) were partially oxidized for the OER reaction. However, CoxP dots on the (100) planes of SrTiO3(Al) for HER kept it as it was. The as-prepared CoxP/SrTiO3(Al) photocatalyst shows a stable HER rate of 1.36 mmol−1 h−1 and OER rate of 0.635 mmol−1 h−1. The strong interaction between CoxP and SrTiO3(Al) not only facilitates rapid charge separation but also provides a highly active site for overall water splitting. Our study provides a valuable method for constructing noble-metal-free SrTiO3(Al)-based photocatalysts.
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