Interfacial Chemical-Bonded MoS₂/In–Bi₂MoO₆ Heterostructure for Enhanced Photocatalytic Nitrogen-to-Ammonia Conversion

Abstract

Photocatalytic nitrogen reduction reaction (pNRR) is considered an ideal NH 3 synthetic technology. Although catalysts prepared for pNRR under mild conditions have been extensively developed, they still face limitations of insufficient N 2 adsorption/ activation and low NH 3 selectivity. Herein, a MoS 2 /In−Bi 2 M O O 6 heterojunction catalyst with an interfacial chemical bond was constructed by the electrostatic self-assembly method. Efficient spatial separation of photogenerated electron/hole pairs and accelerated carrier transfer dynamics were facilitated due to the formation of a Mo−S bond at the interface between MoS 2 and In− Bi 2 MoO 6 . The crystal orbital Hamiltonian population (COHP) analysis further confirmed that the electrons transferred from MoS 2 into the antibonding orbital of N 2 to activate the adsorbed N 2 , favoring nitrogen-to-ammonia (N 2 -to-NH 3 ) conversion. The resultant NH 3 /NH 4 + production rate for 3% MoS 2 /In−Bi 2 MoO 6 reached 90 μmol•g −1 •h −1 , representing a significant improvement over pure Bi 2 MoO 6 , while the production of NO 3 − was minimal. Introducing MoS 2 as a cocatalyst effectively inhibited the oxidation of NH 3 /NH 4 + to NO 3 − , achieving selective pNRR. This work provides a foundation for selective photocatalytic nitrogen fixation, offering valuable insights into the clean production of NH 3 . KEYWORDS: chemical-bonded, MoS 2 /In−Bi 2 MoO 6 heterostructure, photocatalytic nitrogen fixation, selectivity

Flatland materials for photochemical and electrochemical nitrogen fixation applications: from lab-door experiments to large-scale applicability

“…By developing novel TMDs-based heterojunction photocatalysts for energy conversion applications, 26,28 researchers have made satisfactory progress in the past few years, especially for realizing their potential in NRR applications. Recently, Ma et al 100 illustrated the unique interfacial chemical bonding between MoS 2 /In-Bi 2 MoO 6 , which resulted in the enhancement of the NRR performance of the as-developed heterostructured photocatalyst fabricated via electrostatic self-assembly route. The group ascertained the advent of the Mo–S intermolecular chemical bonding between the heterostructured photocatalyst to be the primary influencing factor that facilitated the charge-transfer dynamics at the interfacial contact.…”

SrTiO3:Al/Cd0.6Zn0.4S Type-II Heterojunction Photocatalysts for Efficient Solar Water Splitting

“…However, the wide bandgap (approximately 3.2 eV) of pure SrTiO 3 , which can only absorb 5% of the sunlight, and many bulk or surface defects leading to the high recombination rate of photogenerated carriers limit the application of strontium titanate in the field of photocatalytic water splitting . In recent years, measures such as surface photosensitization, , ion doping, , heterojunction construction, − and loading cocatalyst ,, have been used to improve the photocatalytic performance of semiconductors. Combining band gap appropriate semiconductors to construct a good heterojunction is a powerful method to increase the lifetime and transfer rate of photoinduced charges. , According to the band structure of semiconductors and the direction of carrier transport at the heterojunction interface, common heterojunctions can be divided into type-I, type-II, and Z-type.…”