Amid the global wave of green development, the construction industry—an energy-intensive and high-emission sector—urgently necessitates advanced materials that integrate structural strength with environmental functionality. Photocatalytic technology has emerged as a core direction for upgrading the performance of building materials, thanks to its ability to degrade pollutants and purify the environment at room temperature. As a widely used construction material, cementitious composites incorporated with photocatalysts enable the photodegradation of pollutants, attracting significant attention. However, traditional Portland cement-based photocatalytic materials suffer from high energy consumption and substantial carbon emissions. In contrast, magnesium oxychloride cement (MOC) has become an ideal composite matrix due to its advantages such as rapid setting, high early strength, and excellent pore structure. Nevertheless, existing photocatalysts face prominent bottlenecks: TiO₂ only responds to ultraviolet light, which accounts for less than 5% of sunlight. Although bismuth-based catalysts are compatible with visible light, they suffer from fast charge carrier recombination and low catalytic efficiency, severely hindering large-scale applications. Against this backdrop, the development of high-performance composite photocatalysts and addressing the industry pain point of "difficulty in balancing matrix performance and catalytic efficiency" has become crucial breakthroughs for promoting the environmental upgrading of the construction sector and facilitating the achievement of carbon emission reduction goals.
Recently, a research team in Qinghai Institute of Salt Lakes, CAS. has successfully developed a novel photocatalytic cement-based composite material. A g-C₃N₄/BiOCl₀.₅I₀.₅ composite photocatalyst (BiO-CN2) was synthesized via high-temperature calcination combined with microwave-assisted solvothermal method, and innovatively compounded with magnesium oxychloride cement (MOC) to prepare the high-performance BiOCN/MOC photocatalytic composite. This technology effectively addresses the shortcomings of traditional photocatalysts, such as weak visible light response and fast charge carrier recombination, while significantly enhancing the matrix performance: at a 4% catalyst dosage, the 28-day compressive strength of the composite material is 20.99% higher than that of pure MOC. It exhibits efficient adsorption-chemical synergistic degradation capacity for RhB dye, with simultaneous optimization of self-cleaning performance and structural stability. This research provides an innovative technical pathway for the performance breakthrough of photocatalytic cement-based materials and lays a critical foundation for the large-scale application of green and environmentally friendly functional materials in the construction field.
This work was funded by the National Natural Science Foundation of China (Grant No. 52378266), the China Scholarship Council (No. 202304910299), the Xining "Xiadu Talents" Program, and the Qinghai Province "Kunlun Talents" High-End Innovation and Entrepreneurship Talent Program (2022).
