A chemically bonded photocatalyst with rich oxygen vacancies for improved photocatalytic decontamination

A challenge in promoting the industrial application of photocatalysis technology for environment remediation lies in the design of high-performance photocatalysts. These photocatalysts should be endowed with efficient photo-carrier separation and intense redox potentials to boost photocatalytic pollutant removal.

In a study published in Advanced Powder Materials, a group of researchers from Zhejiang Ocean University and University of Missouri revealed the modulation of interfacial chemical bond of Mn_0.5Cd_0.5S/BiOBr assisted by with rich oxygen vacancies. This, in turn, elucidated the underlying mechanism for boosted photocatalytic performance.

"BiOBr is a visible-light active photocatalyst with several advantages, including a favorable band configuration, exceptional photo-oxidative capacity, distinctive 2D architecture, ecological compatibility, abundant resources and robust durability," explained Shijie Li, co-lead author of the study. "However, constrained absorption of visible light and sluggish photo-carrier diffusion and segregation hamper its practical application."

The team developed an S-scheme photosystem of Mn_0.5Cd_0.5S/BiOBr with interfacial bond and oxygen defects, constructed by pinning Mn_0.5Cd_0.5S nanoparticles on BOB microflowers. This was devised for efficacious decontamination of antibiotics and Cr(VI).

"Physical contact without chemically bonding hetero-interface between the two components, which is insufficiently interactive, generally results in an unsatisfactory charge migration passage," added Bin Zhang, co-lead and co-corresponding author.

"Besides, defect engineering is another effective strategy to upgrade the catalytic property. Thus, precise construction of chemically bonded S-scheme heterojunction with structural defects is essential for efficient photocatalytic water purification but is rarely exploited in photocatalytic applications."

The team's findings provide a feasible approach to developing outstanding catalysts for environmental protection via combining interfacial chemical bonds and defects modulated S-scheme junction.