http://publicationslist.org/data/meng.chong/ref-18/sdarticle.pdf

Recent Developments in Photocatalytic Water Treatment Technology: A Review

Photoinduced reactivity of titanium dioxide

http://repository.ias.ac.in/39608/1/49_pub.pdf

A review of imperative technologies for wastewater treatment I: oxidation technologies at ambient conditions

Semiconductor heterogeneous photocatalysis, the subject of this review, is a versatile, low-cost and environmentally benign treatment technology for a host of pollutants. These may be of biological, organic and inorganic in origin within water and air. The efficient and successful application of photocatalysis demands that the pollutant, the catalyst and source of illumination are in close proximity or contact with each other. The ability of advanced oxidation technology to remove low levels of persistent organic pollutants as well as microorganisms in water has been widely demonstrated and, progressively, the technology is now being commercialized in many areas of the world including developing nations. This review considers recent developments in the research and application of heterogeneous semiconductor photocatalysis for the treatment of low-level concentrations of pollutants in water and air using titanium dioxide as a “model” semiconductor. The review considers charge transport characteristics on the semiconductor surface, photocatalyst reactor design and organic degradation mechanistic pathways. The effects of photoreactor operating parameters on the photocatalytic process are discussed in addition to mineralization and disinfection kinetics.

/pdf/heterogeneous-photocatalysis-recent-advances-and-85shrapqig.pdf

Heterogeneous Photocatalysis: Recent Advances and Applications

Engineering photocatalytic materials for renewable energy generation and environmental decontamination has always been a very exciting prospect to counter the global energy demands and pollution challenges. Graphitic carbon nitride (g-C 3 N 4 ), a polymeric, metal-free semiconductor with a mild band gap (2.7 eV) has become hot-spot in various scientific exploits such as environmental pollution mitigation, energy generation and storage, organic synthesis, sensors, etc. These applications exploit the interesting properties of g-C 3 N 4 such as good visible light absorption, graphene-like structure, good thermal and chemical stability and photocatalytic properties. In this review we begin with an overview of the fundamental aspects of photocatalysis as a pollution remediation strategy. This is followed by an introduction to graphitic carbon nitride as a photocatalyst, preparation strategies and its properties. Subsequently, a comprehensive and critical discussion of the various most recent developments towards enhancing the visible light photocatalytic properties of g-C 3 N 4 for pollution alleviation, selected results and important photocatalytic degradation mechanisms, is given. Summary remarks and future perspective conclude the review.

Graphitic carbon nitride (g-C3N4) nanocomposites: A new and exciting generation of visible light driven photocatalysts for environmental pollution remediation

Photodegradation kinetics of 4-nitrophenol in TiO2 suspension

http://www.eng.uwo.ca/people/aray/Ajay%20Publications%20PDF%20files/A28%20Dingwang%20CES%202001.pdf

Removal of toxic metal ions from wastewater by semiconductor photocatalysis

In recent years, photocatalytic degradation mediated by illuminated TiO2 has received considerable attention as an alternative for treating polluted water. In the present study, a new two-phase swirl-flow monolithic-type reactor was used to study the kinetics of heterogeneous photocatalytic processes. Photocatalytic degradation of phenol, 4-chlorophenol (4-CP) and 4-nitrophenol (4-NP) both in aqueous suspensions and over immobilized Degussa P25 TiO2 has been studied in laboratory scale. Experiments were conducted to investigate the effects of parameters such as catalyst dosage, pollutant concentration, temperature, partial pressure of oxygen, UV light intensity, catalyst-layer thickness, circulation flowrate and catalyst annealing temperature. Simple model for predicting the optimal catalyst dosage in aqueous suspensions for different photo-systems was proposed. Pseudo first-order kinetics with respect to all the parent compounds was observed. Experimental data obtained under different conditions were fitted with kinetic equation to describe the dependency of degradation rate as a function of the above mentioned parameters. Consequently, kinetic parameters were experimentally determined. Adsorptive properties of all the organics were also experimentally measured and fitted with Langmuir equation. The extreme low surface coverage of the organics on the catalyst may be one of the main factors that result in the low efficiency of the photocatalytic process. Besides, mass transfer of organics and oxygen in the photocatalytic process has also been discussed in detail. ©1999 Elsevier Science B.V. All rights reserved.

/pdf/photocatalytic-kinetics-of-phenol-and-its-derivatives-over-2f58rgxyoi.pdf

Photocatalytic kinetics of phenol and its derivatives over UV irradiated TiO2

Semiconductor photocatalytic processes hae been studied for nearly 20 years due to their intriguing adantages in enironmental remediation. A rational approach in deter- mining the effect of mass transfer and catalyst layer thickness during photocatalytic reactions is proposed. The reaction occurs at the liquid ) catalyst interface, and therefore when the catalyst is immobilized, both external and internal mass transfer plays signifi- cant roles in oerall photocatalytic processes. Seeral model parameters} external mass-transfer coefficient, dynamic adsorption equilibrium constant, adsorption rate constant, internal mass-transfer coefficient, and effectie diffusiity } were determined either experimentally or by fitting realistic models to experimental results using benzoic acid as a model component. Een though all these parameters are critical to the design and deelopment of photocatalytic processes, they are not aailable in the literature. The effect of the internal mass transfer on the photocatalytic degradation rate oer different catalyst layer thicknesses under two different operating configurations was ana- lyzed theoretically and experimentallyerified. It was obsered that an optimal catalyst layer thickness exists for substrate-to-catalyst illumination.

/pdf/effect-of-mass-transfer-and-catalyst-layer-thickness-on-2qz5gontf0.pdf

Effect of mass transfer and catalyst layer thickness on photocatalytic reaction

https://www.eng.uwo.ca/people/aray/Ajay%20Publications%20PDF%20files/A30%20Dingwang%20Cat%20Today%202001.pdf

Dingwang Chen

Papers

Photodegradation kinetics of 4-nitrophenol in TiO2 suspension

Removal of toxic metal ions from wastewater by semiconductor photocatalysis

Photocatalytic kinetics of phenol and its derivatives over UV irradiated TiO2

Effect of mass transfer and catalyst layer thickness on photocatalytic reaction

External and internal mass transfer effect on photocatalytic degradation