Pt nanoparticles embedded spine-like g-C <sub>3</sub> N <sub>4</sub> nanostructures with superior photocatalytic activity for H <sub>2</sub> generation and CO <sub>2</sub> reduction
Xiao Zhang, Ping Yang, San Ping Jiang
Abstract
Abstract Conventional two-dimensional (2D) graphitic carbon nitride, 2D g-C 3 N 4 with its layered structures and flat and smooth 2D surface possesses certain disadvantages that is affecting their photocatalytic performances. In this paper, new nanostructured spine-like three-dimensional (3D) g-C 3 N 4 nanostructures are created for the first time via a new three-step synthesis method. In this method, self-assembly of layered precursors and H + intercalation introduced by acid treatment play an important role for the unique nanostructure formation of 3D g-C 3 N 4 nanostructures. The spine-like 3D g-C 3 N 4 nanostructures show a superior photocatalytic performance for H 2 generation, achieving 4500 μ mol·g −1 ·h −1 , 8.2 times higher than that on conventional 2D g-C 3 N 4 . Remarkably spine-like 3D g-C 3 N 4 nanostructures demonstrate a clear photocatalytic activity toward CO 2 reduction to CH 4 (0.71 μ mol·g −1 ·h −1 ) in contrast to the negligible photocatalytic performance of conventional 2D g-C 3 N 4 for the reaction. Adding Pt clusters as co-catalysts substantially enhance the CH 4 generation rate of the 3D g-C 3 N 4 nanostructures by 4 times (2.7 μ mol·g −1 ·h −1 ). Spine-like 3D g-C 3 N 4 caged nanostructure leads to the significantly increased active sites and negatively shifted conduction band position in comparison with conventional 2D g-C 3 N 4 , favorable for the photocatalytic reduction reaction. This study demonstrates a new platform for the development of efficient photocatalysts based on nanostructured 3D g-C 3 N 4 for H 2 generation and conversion of CO 2 to useful fuels such as CH 4 .