Search results for "heterogeneous"

Photocatalytic processes in membrane reactors

2017

Photocatalytic membrane reactors (PMRs) represent an interesting alternative technology useful both in the field of water and air purification and in organic syntheses. The necessity to develop chemical products and industrial processes that reduce or eliminate the use and the generation of toxic substances along with the risk for human health and for environment constitutes the aim of the research efforts based on the principles of green chemistry. Heterogeneous photocatalysis is a technology extensively studied for about three decades, since Fujishima and Honda1 discovered the photocatalytic splitting of water on TiO2 electrodes in 1972, which includes a large range of reactions. When a s…

Photo-assisted Degradation of 2-Propanol in Gas-Solid Regime by Using TiO2 Impregnated with Heteropolyacids H3PW12O40

2009

Commercial and home prepared TiO2 samples impregnated with tungstophosphoric acid (H3PW12O40) were used for the photo-assisted degradation of 2-propanol in gas–solid regime. The characterization results evidenced a good coverage of the polyoxometalate (POM) onto the surface of TiO2 along with a marginal effect of the presence of the POM on the specific surface area, morphology and cristallinity of the samples. Propene was the main intermediate product revealed in 2-propanol photocatalytic degradation by using as photocatalysts the samples containing the POM, whereas propanone wasmainly obtained when the photocatalysts was bare TiO2, both commercial or home prepared. Acetaldehyde was also fo…

Photodegradation of pharmaceutical drugs in aqueous TiO2 suspensions: mechanism and kinetics

2007

WOS: 000251165800003

Selectivity of hydroxyl radical in the partial oxidation of aromatic compounds in heterogeneous photocatalysis

2007

Abstract The photocatalytic oxidation of different benzene derivatives has been investigated in order to understand how the substituent group affects the selectivity to hydroxylated compounds. Experimental runs were performed by using TiO2 (Merck) aqueous suspensions at natural pH irradiated by near-UV light. The organic molecules used as substrate contained an electron withdrawing group (EWG) (nitrobenzene, cyanobenzene, benzoic acid, 1-phenylethanone), an electron donor one (EDG) (phenol, phenylamine, N-phenylacetamide) or both an EWG and an EDG (4-chlorophenol). The results clearly indicated that the primary photocatalytic oxidation of aromatic compounds containing an EDG gives rise main…

Advances in selective conversions by heterogeneous photocatalysis

2010

Selective photocatalytic conversions are offering an alternative green route for replacing environmentally hazardous processes with safe and energy efficient routes. This paper reports the most recent advances in the application of heterogeneous photocatalysis to synthesize valuable compounds by selective oxidation and reduction.

Formation of high added value chemicals by photocatalytic treatment of biomass

2020

The depletion of fossil fuel requires the search for alternative renewable feedstock and environmentally friendly methods for the production of high value-added compounds and fuels. In this context, the efficient use of biomass has emerged as a significant research field as it represents an alternative green and renewable carbon source. Various technologies have been explored for this purpose and heterogeneous photocatalysis represents a valid alternative to the catalytic methods since it can be carried out under mild experimental conditions without the addition of harmful oxidizing agents. Different biomass components have been used as the starting materials, and many valuable chemicals h…

Facile preparation of CuBi2O4/TiO2 hetero-systems employed for simulated solar-light selective oxidation of 4-methoxybenzyl alcohol model compound

2023

The selective photocatalytic oxidation of organic substances is today considered one of the green techniques to synthesize important starting materials in different technological applications. This work reports an efficient, simple and cheap strategy for the synthesis of a new photocatalytic CuBi2O4-TiO2 (CBO/TiO2) heterosystem at room temperature. The prepared powders were characterized by X-ray diffraction (XRD), UV–Vis diffuse reflectance spectra (DRS), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. The photocatalytic activity was evaluated by performing a probe reaction, namely the partial oxidation of 4-me…

Heterogeneous photocatalysis: a promising advanced oxidation process

2018

This chapter reports the fundamentals of heterogeneous PC. In particular, different kinetic models and the influence of some parameters (such as pH, temperature, light intensity) on the rate of PC are described, and the effects of some photocatalyst modifications are discussed. Methods for photoreactor modeling are analyzed and the coupling of PC with other AOPs using H2O2, O3, and peroxydisulfate are discussed.

Membranes for photocatalysis in wastewater treatment

2011

Determination of Photoadsorption Capacity of Polychrystalline TiO2 Catalyst in Irradiated Slurry

2009

WOS: 000322711800002