Interface-Engineered Frustrated Lewis Pairs in the α-Ga₂O₃/β-In₂O₃ Heterostructure for Efficient Photocatalytic CO₂...

Area of Science:

• Materials Science
• Catalysis
• Photochemistry

Background:

• Developing efficient photocatalysts for carbon dioxide (CO2) reduction is hindered by poor charge dynamics and CO2 activation.
• Frustrated Lewis acid-base pairs (FLPs) show promise for activating small molecules like CO2.

Purpose of the Study:

• To engineer oxygen vacancy-tailored FLPs within α-Ga2O3/β-In2O3 heterostructures for enhanced CO2 reduction.
• To investigate the role of interfacial FLPs in CO2 activation and conversion mechanisms.

Main Methods:

• Fabrication of α-Ga2O3/β-In2O3 heterostructures using a two-step ion-exchange and annealing process.
• Characterization of the multiphase interface and oxygen vacancies.
• Photocatalytic CO2 reduction experiments without sacrificial agents, monitoring CO production rates.

Main Results:

• Successfully constructed spatially separated In3+ (Lewis acids) and Ga-O (Lewis bases) FLPs at the biphasic interface.
• The optimized FLP configuration significantly enhanced charge separation and carrier lifetime.
• Achieved a CO production rate of 27.7 μmol·g−1·h−1, a 2.2-fold increase compared to pristine β-In2O3.

Conclusions:

• The engineered FLPs effectively synergistically polarize CO2 molecules, facilitating efficient reduction.
• FLPs promote the formation of bidentate carbonate as a key intermediate, leading to CO production.
• This work establishes a general strategy for designing high-performance photocatalysts via interfacial defect engineering for CO2 utilization.