Hybridization-Driven Introduction of Anion Vacancies to Boost the Photocatalytic Nitrogen Fixation Functionality of Low-Lattice-Energy Nanosheets
Taehoon Kim, Min Jae Kang, Nam Hee Kwon, Yoon Chang Hong, Xiaoyan Jin, Minho Kim, Seong‐Ju Hwang
Abstract
Defect engineering has attracted considerable research interest owing to its effectiveness in optimizing the catalytic performance of inorganic solids. Herein, we develop a hybridization-assisted defect control approach to fabricate efficient visible-light-active photocatalysts comprising low-lattice-energy nanosheets via a synergetic combination of hybridization and defect engineering. The hybridization between Cu–Cr-layered double hydroxide (Cu–Cr-LDH) and g-C 3 N 4 nanosheets having relatively low lattice energies effectively increases the defect concentration and improves photocatalyst performance for the visible-light-driven N 2 reduction reaction (NRR). Using defect-introduced holey g-C 3 N 4 nanosheets as building blocks further reinforces the interfacial interaction with the hybridized Cu–Cr-LDH nanosheets, producing additional crystal defects. The defective g-C 3 N 4 –Cu–Cr-LDH nanohybrid exhibits exceptional NRR activity showing an outstanding NH 4 + formation rate of 1.45 mmol h –1 g cat –1 and one of the best NRR catalytic performances among the recently reported LDH-based photocatalysts. Combined in situ spectroscopic analysis and theoretical calculation reveal that the reinforced coupling with vacancy-introduced g-C 3 N 4 nanosheets effectively improves the photocatalytic activity and stability of Cu–Cr-LDH via the facilitation of the associative reaction pathway. The high efficacy of hybridization-assisted defect control for efficient generation of photocatalysts is attributable to the mutual enhancement of defect concentration and interfacial interaction, which improves N 2 adsorption/activation, light absorption, and charge transport properties and prevents the recombination of electron–hole pairs.