Solar photothermo-catalysis is a fascinating multi-catalytic approach for volatile organic compounds (VOCs) removal. In this work, we have explored the performance and the chemico-physical features of non-critical, noble, metal-free MnOx-ZrO2 mixed oxides. The structural, morphological, and optical characterizations of these materials pointed to as a low amount of ZrO2 favoured a good interaction and the ionic exchange between the Mn and the Zr ions. This favoured the redox properties of MnOx increasing the mobility of its oxygens that can participate in the VOCs oxidation through a Mars-van Krevelen mechanism. The further application of solar irradiation sped up the oxidation reactions promoting the VOCs total oxidation to CO2. The MnOx-5 wt.%ZrO2 sample showed, in the photothermo-catalytic tests, a toluene T90 (temperature of 90% of conversion) of 180 °C and an ethanol T90 conversion to CO2 of 156 °C, 36 °C, and 205 °C lower compared to the thermocatalytic tests, respectively. Finally, the same sample exhibited 84% toluene conversion and the best selectivity to CO2 in the ethanol removal after 5 h of solar irradiation at room temperature, a photoactivity similar to the most employed TiO2-based materials. The as-synthetized mixed oxide is promising for an improved sustainability in both catalyst design and environmental applications.

La 2 O 2 CO 3 -WO 3 composites were here proposed as unconventional photocatalysts for the removal of phthalates in water. The high sorption properties of the lanthanum dioxide carbonate allowed a strong adsorption of the phthalates which facilitated the following solar photocatalytic degradation, further boosted by the addition of small amounts of WO 3 (1 wt %). On the contrary, a higher content of WO 3 had a detrimental effect due to the covering of the surface sites of La 2 O 2 CO 3 that inhibited the adsorption process. This double mechanism of strong adsorption-photocatalytic oxidation led, after 6 h of solar irradiation, to 67 % and 63 % dimethyl phthalate and di(2ethylhexyl)phthalate degradation, respectively. The phthalates were degraded to less persistent pollutants that, however, were completely removed after 9 h of irradiation. The La 2 O 2 CO 3 -WO 3 system appears promising for its application in the removal of the emerging contaminants from water.[a] E.

Nowadays, the presence of pollutants in water is an urgent problem to solve. The efficient removal of these contaminants from aqueous solutions requires advanced oxidation processes (AOPs). This can be accomplished by various approaches using materials that allow the rapid removal of pollutants with high degradation rates. In this work, we focused on the surface modification of TiO2 films for photocatalytic application in water remediation. In particular, with an appropriate surface functionalization with zirconium phosphate, we have improved the sensitivity to sunlight and the thermal stability of TiO2. The surface functionalization of the samples was verified by using TOF-SIMS, which allows us to obtain spatially resolved chemical information. This information is very helpful for an effective engineering of the material, in order to obtain the best performances for environmental remediation. To our knowledge, this is the first time that TOF-SIMS is used to monitor the evolution of photocatalytic reactions at the photoactive surface, getting information on degradation pathways taking place at the surface of the photoactive material under solar light irradiation. In this work, as a target molecule, we chose rhodamine B, a dye widely used in textile industry, among others. The investigation of the degradation pathways occurring directly at the samples’ surface can provide relevant information about the rate determining step of the reaction and give hints for tailored functionalization of materials for improving their photocatalytic performances.