Making Marble Powder Waste Profitable by Using Nano-TiO₂ Surface Modification for Air Quality Improvement Applications

Abstract

We report a brand new recycling route of waste marble powder, by means of surface modification with homemade nano-TiO 2 particles to produce low cost coating materials for the application in air quality improvement. The as-prepared nano-TiO 2 in 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-TiO 2 clad 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.

Waterproof Aerated Bricks from Stone Powder Waste through Nano-TiO2 Structured Hydrophobic Surface Modification

“…The crystal phase of the prepared TiO2 was revealed by XRD ( Figure S2 in the supplementary materials). The diffraction peaks located at 25.2°, 37.7°, 48.0°, 53.9°, 62.6° were well indexed to its (101), (004), (200), (105) and (204) reflections respectively (JCPDS Card Number 21-1272), indicating anatase crystal structure of TiO2 [1]. The dispersion characteristic of TiO2, which can be evaluated by the degree of nanoparticles aggregation in water, is of crucial importance to the aqueous based suspension fabrication.…”

“…The aerated brick was dipped into the TiO2 based aqueous super-hydrophobic suspension, introducing the micro-and nanostructure on the outmost The highly dispersive TiO 2 nanoparticles in water were prepared, enabling the preparation of environmentally friendly aqueous based suspension. Being a wide gap semiconductor [22,23] and nontoxic material, TiO 2 has been extensively used in areas of solar cells [23], photocatalysis [1], whitening, and ultraviolet shielding. The crystal phase of the prepared TiO 2 was revealed by XRD ( Figure S2 in the Supplementary Materials).…”

“…In this study, the aerated brick surface was coated with a novel homemade self-dispersed TiO 2 nanoparticle to form the hydrophobic hierarchical double structure. The TiO 2 particles were synthesized through a controllable hydrothermal reaction, as described in our previous studies [1,6,16]. In this research, firstly, 5 g of TiO 2 nanoparticles were dispersed into 20 ml of a mixture solution of water and ethylene glycol (purchased form Sigma-Aldrich) at a ratio of 1:1.…”

“…Owing to the increasing demand for stone construction and decoration materials world wide because of the continuing growth in the world's population, a tremendous amount of stone powder waste has been generated in the natural and artificial stone industry during the cutting and carving processing stages, which could account for up to 35% of the weight of the stone that was used. The waste powder ranging from nanometers to millimeters is disposed of in landfills or arbitrarily discharged to the surrounding environment, and is prone to drift in air, which has not only caused severe environmental and ecological damage, but also carried risks to public health [1]. Fortunately, a growing awareness of these issues has been raised by both local municipal managers and many researchers from different fields.…”

“…At present, the reuse strategies concentrate upon incorporating the stone byproduct as additives into the traditional construction materials, such as cement and concrete, to regulate their mechanical properties [2][3][4][5]. Other applications for reusing the stone powder have been developed by researchers in the area of functional nanomaterials, such as a self-cleaning coating based on waste marble [6], or a marble powder derived paint for indoor air quality improvement [1]. However, the stone powder is reused as a type of auxiliary material, which consumes a pretty negligible amount of waste.…”