Assembling Graphene-Encapsulated Pd/TiO2 Nanosphere with Hierarchical Architecture for High-Performance Visible-Light-Assisted Methanol Electro-Oxidation Material

• Published in: Industrial & engineering chemistry research 2019-10, Vol.58 (42), p.19486-19494
• Main Authors: Zhang, Bing, Yang, Fan, Liu, Hongchen, Yan, Linan, Yang, Wang, Xu, Chong, Huang, Shuo, Li, Qi, Bao, Weijie, Liu, Bei, Li, Yongfeng
• Format: Article
• Language: English
• Subjects: active sites; catalysts; catalytic activity; electrochemistry; encapsulation; graphene; graphene oxide; lighting; methanol; nanoparticles; nanospheres; oxidation; palladium; particle size; process design; titanium dioxide
• ISSN: 0888-5885; 1520-5045; 1520-5045
• DOI: 10.1021/acs.iecr.9b03619

Photoactivated methanol oxidation electrocatalysis attracts broad interest in recent years. Herein, we report the novel reduced graphene oxide encapsulated with a Pd-modified TiO2 nanosphere (PTG) hierarchical composite by the electrostatic assembly strategy. The homodisperse tiny palladium nanoparticles (Pd NPs) on the TiO2 support (Pd/TiO2) ensure more active sites exposed, and graphene encapsulation ensures rapid electron transmission and high light utilization of the PTG material. This tailor-made composite exhibits not only high catalytic activity up to 1052 mA/mg but also good stability due to its distinct hierarchical structure and strong interaction between Pd/TiO2 core and graphene shell. Moreover, detailed characterizations showed that the properties of PTG are related to the particle size and crystal phase of the TiO2 support. The optimal PTG-400-650 (TiO2 support with mixed crystal and particle size of 400 nm) displays 2.0-fold enhancement in catalytic activity under light illumination, which is superior to previously reported TiO2-based photoelectrocatalysts.