Making Marble Powder Waste Profitable by Using Nano-TiO₂Surface Modification for Air Quality Improvement Applications

We report a brand new recycling route of waste marble powder, by means of surface modification with homemade nano-TiO2particles to produce low cost coating materials for the application in air quality improvement. The as-prepared nano-TiO2in anatase phase exhibits excellent photocatalytic characteristic, reflected by the high degradation rate of over 95% of methylene blue within 6 hours of UV irradiation. The prepared coating consisting of nano-TiO2clad marble powder was tested by monitoring the decomposition rate of formaldehyde gas. A high degradation efficiency of about 95% within 9 hours of illumination is achieved, demonstrating a promising potential for removing the harmful and toxic organic pollutants in air while applying this coating in buildings both interiorly and exteriorly.