Molybdate

Chemisorption

Catalysis

Adsorption

Engineering

Photochemistry

Metallurgy

Materials science

Layer (electronics)

Inorganic chemistry

Chemical engineering

Nitrogen

Homojunction

Physical chemistry

Bismuth

Nanotechnology

Organic chemistry

Oxygen

Doping

Bromine

Aqueous solution

Surface modification

Chemistry

Surface layer

Photocatalysis

Optoelectronics

Applied Catalysis B Environment and Energy

The oxygen vacancy (Ov) in photocatalysts plays a significant role for N2 fixation, but effective and simple means for creation of Ov are in urgent demand. Herein, surface-layer Br doping was confirmed to create massive surface Ov in Bi2MoO6 in a solvothermal process, with the product (BMO-Br-Ov) exhibiting remarkably enhanced N2 chemisorption and activation, photoinduced charge separation, and thus photocatalytic N2 fixation, compared with bulk Bi2MoO6, with an apparent quantum yield at 420 nm reaching 0.52% in pure water and 2.56% in the methanol aqueous solution. The charge separation enhancement benefits from the Ov introduced defect level and Br doping and surface Ov modification induced band-level difference between the surface and the inside in BMO-Br-Ov that leads to fabrication of the surface/inside homojunction. This work provides a simple way to create surface Ov in Bi2MoO6 and may direct Ov creation in other Bi-based photocatalysts for efficient N2 fixation.

Surface-layer bromine doping enhanced generation of surface oxygen vacancies in bismuth molybdate for efficient photocatalytic nitrogen fixation