Reduced TiO2-Graphene Oxide Heterostructure As Broad Spectrum-Driven Efficient Water-Splitting Photocatalysts

详细信息    查看全文

• 作者：Lihua Li ; Lili Yu ; Zhaoyong Lin ; Guowei Yang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：April 6, 2016
• 年：2016
• 卷：8
• 期：13
• 页码：8536-8545
• 全文大小：707K
• ISSN：1944-8252

文摘

The reduced TiO₂-graphene oxide heterostructure as an alternative broad spectrum-driven efficient water splitting photocatalyst has become a really interesting topic, however, its syntheses has many flaws, e.g., tedious experimental steps, time-consuming, small scale production, and requirement of various additives, for example, hydrazine hydrate is widely used as reductant to the reduction of graphene oxide, which is high toxicity and easy to cause the second pollution. For these issues, herein, we reported the synthesis of the reduced TiO₂-graphene oxide heterostructure by a facile chemical reduction agent-free one-step laser ablation in liquid (LAL) method, which achieves extended optical response range from ultraviolet to visible and composites TiO_2–x (reduced TiO₂) nanoparticle and graphene oxide for promoting charge conducting. 30.64% Ti³⁺ content in the reduced TiO₂ nanoparticles induces the electronic reconstruction of TiO₂, which results in 0.87 eV decrease of the band gap for the visible light absorption. TiO_2–x-graphene oxide heterostructure achieved drastically increased photocatalytic H₂ production rate, up to 23 times with respect to the blank experiment. Furthermore, a maximum H₂ production rate was measured to be 16 mmol/h/g using Pt as a cocatalyst under the simulated sunlight irradiation (AM 1.5G, 135 mW/cm²), the quantum efficiencies were measured to be 5.15% for wavelength λ = 365 ± 10 nm and 1.84% for λ = 405 ± 10 nm, and overall solar energy conversion efficiency was measured to be 14.3%. These findings provided new insights into the broad applicability of this methodology for accessing fascinate photocatalysts.