Highly dispersed g-C3N4 on well-designed three-dimensional porous nanostructured ZrO2 for high-performance photocatalytic degradation and H2 production

Luyao Niu; Jiayu Xin; Jie Liu; Yu Liu; Xi Wu; Fang Zhang; Xiaowei Li; Changlu Shao; Xinghua Li; Yichun Liu

doi:10.1016/j.jcis.2023.01.120

Highly dispersed g-C₃N₄ on well-designed three-dimensional porous nanostructured ZrO₂ for high-performance photocatalytic degradation and H₂ production

J Colloid Interface Sci. 2023 May 15:638:324-338. doi: 10.1016/j.jcis.2023.01.120. Epub 2023 Jan 28.

Authors

Luyao Niu¹, Jiayu Xin¹, Jie Liu¹, Yu Liu¹, Xi Wu¹, Fang Zhang¹, Xiaowei Li¹, Changlu Shao², Xinghua Li³, Yichun Liu¹

Affiliations

¹ Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China.
² Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China. Electronic address: clshao@nenu.edu.cn.
³ Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China. Electronic address: lixh781@nenu.edu.cn.

PMID: 36746051
DOI: 10.1016/j.jcis.2023.01.120

Abstract

A novel polymer-assisted freeze-drying method was adopted for preparing three-dimensional porous nanostructured ZrO₂ (3DPZ) with macro self-supporting properties. Then, g-C₃N₄ was in-situ grown uniformly on the 3DPZ through a gas-solid reaction, forming 3D nanoporous ZrO₂/g-C₃N₄ heterojunctions (3DP/ZC) with different g-C₃N₄ loadings that retained self-supporting characteristics. The k_app value of Rhodamine B (RhB) degradation and H₂ evolution rate of the 3DP/ZC-2 under visible light reached 0.035 min^-1 and 1013.1 μmol h^-1 g^-1, which were 19.6 and 6.6 times higher than pure g-C₃N₄, respectively. The ZrO₂ nanoparticles (ZNps) prepared via freeze-drying, but without polymer precursor, were used as support to form ZrO₂/g-C₃N₄ nanoparticles (ZCNps-2) for comparison study. The RhB degradation rate and H₂ evolution rate of the 3DP/ZC-2 under visible light were about 3.7 and 5.3 times higher than ZCNps-2. Their enhanced photocatalytic activity could be attributed to their unique 3D heterointerface with matched energy bands for rapid charge separation and transfer and a hierarchical porous structure for mass transfer and surface reaction processes. The scavenger trapping and ESR measurements confirmed that the primary reactive radicals for degradation were superoxide radical ions (^⋅O₂^-), hydroxyl radicals (^⋅OH), and photogenerated holes (h⁺). The pH-dependent photocatalytic degradation activity originated from the H⁺-related ^⋅OH conversion reaction. Besides, the macro self-supporting nature could provide excellent separability and recyclability, and self-supporting membranes were also constructed and demonstrated as stable and recyclable photocatalysts. This work provides a new routine for designing 3D-heterojunctions as new kinds of functional materials for applications in environmental remediation and green energy production.

Keywords: 3D porous nanostructure; Heterojunctions; Photocatalyst; ZrO(2); g-C(3)N(4).