Solid acids accelerate the photocatalytic hydrogen peroxide synthesis over a hybrid catalyst of titania nanotube with carbon dot

• Published in: Applied catalysis. B, Environmental Vol. 244; pp. 594 - 603
• Main Authors: Ma, Runyuan, Wang, Liang, Wang, Hai, Liu, Ziyu, Xing, Mingyang, Zhu, Longfeng, Meng, Xiangju, Xiao, Feng-Shou
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05-05-2019; Elsevier BV
• Subjects: Alternative energy sources; Cadmium; Carbon; Carbon dots; Carbon nitride; Catalysis; Catalysts; Chemical energy; Chemical synthesis; Clean energy; Energy conversion; Energy conversion efficiency; Energy storage; H2O2 synthesis; Hydrogen peroxide; Irradiation; Light irradiation; Metals; Nanotubes; Noble metals; Organic chemistry; Oxygen; Photocatalysis; Photocatalyst; Photovoltaic cells; Productivity; Protons; Radiation; Solar energy; TiO2 nanotubes; Titanium dioxide; TiO2 nanotubes; Carbon dots; Photocatalyst; H2O2 synthesis
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2018.11.087

[Display omitted]
•A hybrid catalyst of H-form titania tanotube-carbon dot (HTNT-CD) was developed.•HTNT-CD is efficient for photocatalytic synthesis of H2O2.•The solar-to- H2O2 apparent energy conversion efficiency could reach 5.2%.•The protons accelerate the half reaction of O2 reduction to form H2O2.
Photocatalytic synthesis of hydrogen peroxide (H2O2) from water and oxygen is an alternative route for clean energy storage and chemical synthesis, but still having problems with insufficient H2O2 productivity and solar-to-chemical energy conversion efficiency. Herein, we reported a hybrid catalyst of proton-form titania nanotube with carbon dot (HTNT-CD) that is highly efficient for the production of H2O2 under visible-light irradiation (λ > 420 nm, H2O2 productivity at 3.42 mmol gcat−1⋅h−1), outperforming the titania catalysts containing noble metals and the carbon nitride catalysts reported previously. Multiple studies demonstrate that the protons on the HTNT-CD are crucial for the production of H2O2 by efficiently accelerating the half reaction of molecular oxygen reduction to form H2O2, and effectively hindering H2O2 decomposition under the irradiation conditions. This HTNT-CD catalyst gives solar-to-H2O2 apparent energy conversion efficiency at 5.2%, which is even 4.9 times of that (1.06%) over the catalyst derived from commercial P25 and CDs. More importantly, the HTNT-CD is stable, giving high H2O2 productivity in the continuous recycle tests.