Solvent Etching Process for Graphitic Carbon Nitride Photocatalysts Containing Platinum Cocatalyst: Effects of Water Hydrolysis on Photocatalytic Properties and Hydrogen Evolution Behaviors

In this study, we synthesized Pt/g-C<sub>3</sub>N<sub>4</sub> photocatalysts modified by a solvent etching process where ethanol (Pt/CN0), water (Pt/CN100), and a 50:50 mixture (Pt/CN50) were used as a solvent, and investigated the optimal properties of g-C<sub>3</su...

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Bibliographic Details
Main Authors: Thi Van Anh Hoang, Thi Kim Anh Nguyen, Duc Quang Dao, Phuong Anh Nguyen, Dong Hwi Jeong, Eun Woo Shin
Format: Article
Language:English
Published: MDPI AG 2022-04-01
Series:Nanomaterials
Subjects:
Online Access:https://www.mdpi.com/2079-4991/12/7/1188
Description
Summary:In this study, we synthesized Pt/g-C<sub>3</sub>N<sub>4</sub> photocatalysts modified by a solvent etching process where ethanol (Pt/CN0), water (Pt/CN100), and a 50:50 mixture (Pt/CN50) were used as a solvent, and investigated the optimal properties of g-C<sub>3</sub>N<sub>4</sub> to prepare the best Pt/g-C<sub>3</sub>N<sub>4</sub> for photocatalytic hydrogen evolution. From diverse characterizations, water was proven to be a stronger solvent agent, resulting in not only the introduction of more O-functional groups onto the g-C<sub>3</sub>N<sub>4</sub> surface, but also the degradation of a regular array of tri-s-triazine units in the g-C<sub>3</sub>N<sub>4</sub> structure. While the addition of O-functional groups positively influenced the oxidation state of the Pt cocatalyst and the hydrogen production rate, the changes to g-C<sub>3</sub>N<sub>4</sub> structure retarded charge transfer on its surface, inducing negative effects such as fast recombination and less oxidized Pt species. Pt/CN50 that was synthesized with the 50:50 solvent mixture exhibited the highest hydrogen production rate of 590.9 µmol g<sup>−1</sup>h<sup>−1</sup>, while the hydrogen production rates of Pt/CN0 (with pure ethanol solvent) and Pt/CN100 (with pure water solvent) were 462.7, and 367.3 µmol g<sup>−1</sup>h<sup>−1</sup>, respectively.
ISSN:2079-4991