Synthesis and Photocatalytic Performance of Calcined Zn–Al–Ti-Lamellar Double Hydroxides for Building Material Applications

Abstract

The promising capabilities of elaborated nanocomposites may provide a remarkable advance for successful application in the area of wastewater and organic pollutants treatment in the field of building materials. This paper aims to investigate the photocatalytic properties of calcined lamellar double hydroxides based on Zn–Al–Ti (LDH-ZAT) for the self-cleaning application of building materials. LDH-ZAT powder was synthesized and characterized by XRD, SEM and UV–vis DRS. Then, the synthesized nanocomposite was incorporated into Portland cement (1, 3 and 5 wt%) and analyzed by isothermal microcalorimetry at early age and, XRD and SEM after 90 days to study their compatibility. LDH-ZAT is a semiconductor material and its light absorption performance in the visible light region was highly pronounced (400–420 nm). The addition of LDH-ZAT in Portland cement led to a delay in the heat flow of hydration at an early age. However, various hydrated phases including Zn and Al compounds appeared with curing time showing a growth and development of the microstructure. The photocatalytic activity of cement mortars based LDH-ZAT was evaluated by the photodegradation of Rhodamine B (Rh-B) dye within 240 min of UV irradiation. The increase of LDH-ZAT in blended mortars showed an important efficacy for the degradation of Rh-B dye. Up to 1 and 5 wt% of synthesized LDH-ZAT showed a degradation of 25.06% and 37.62% of Rh-B (10 mg L−1), respectively. The kinetics of Rh-B dye photodegradation process correlates well with the Pseudo-first-order model. Moreover, LDH-ZAT revealed a significant self-cleaning surface of mortars under the sunlight.