The Effect of Interfacial Chemical Bonding in TiO2-SiO2 Composites on their Photocatalytic NOx Abatement Performance

The authors gratefully acknowledge funding from the UK Engineering and Physical Sciences Research Council (Grant Ref: EP/M003299/1) and the Natural Science Foundation of China (No. 51461135005) International Joint Research Project (EPSRC-NSFC).Peer reviewedPublisher PD

Photocatalyst efficiencies in concrete technology : the effect of photocatalyst placement

The authors gratefully acknowledge funding from the UK Engineering and Physical Sciences Research Council (Grant Ref: EP/M003299/1) and the Natural Science Foundation of China (No. 51461135005, No. 51478370) International Joint Research Project (EPSRC-NSFC).Peer reviewedPublisher PD

Novel photocatalytic organic synthesis : cyclization and N-alkylation of nitroaromatic compounds

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Factors affecting the selectivity of the photocatalytic conversion of nitroaromatic compounds over TiO2 to valuable nitrogen-containing organic compounds

The photocatalytic conversion of various nitroaromatic compounds in alcohols employing four different types of TiO2 (Sachtleben Hombikat UV100 as anatase, Crystal Global R34 as rutile, Evonik-Degussa Aeroxide P25 as an anatase-rutile mixture, and home-made mesoporous anatase) has been studied. The effect of platinization of these different types of TiO2 on the reaction sequence has also been investigated. Upon irradiation of an ethanolic solution of m-nitrotoluene, as a model reaction, in the presence of the bare photocatalyst, different products were obtained according to the applied photocatalyst. It was found that the surface properties of the photocatalyst play an important role in the reaction pathway and thus in the selectivity of the products. In all cases, a simultaneous reduction of the nitro compound and an oxidation of the alcohol are induced by the photogenerated electrons and holes, respectively. An imine is then produced upon condensation of the generated aldehyde and amino compounds. Rutile was found to be more selective towards the primary amino compound (m-toluedine) while anatase catalysts gave a mixture of m-toluidine and its imine (N-ethylidene-3-methylaniline). A cyclization reaction of the produced imine to generate methyl quinoline was observed when Aeroxide P25 was used as a photocatalyst. Employing platinized TiO2, the hydrogenation of the produced imine yielding N-alkylated products was found to occur in all cases. However, the selectivity towards the mono N-alkylated product was the best using platinized Hombikat UV100. This selectivity was found to be also influenced by the loaded amount of Pt, the platinization method, and the illumination time but not by the light intensity.© 2013 the Owner Societies

The Different Roles of Water in Photocatalytic DeNOx Mechanisms on TiO2 : A Basis for Engineering Nitrate Selectivity?

The authors gratefully acknowledge funding from the UK Engineering and Physical Sciences Research Council (Grant Ref: EP/M003299/1) and the Natural Science Foundation of China (No. 51461135005) International Joint Research Project (EPSRC-NSFC).Peer reviewedPostprin

Boosting the H2 Production Efficiency via Photocatalytic Organic Reforming: The Role of Additional Hole Scavenging System

The simultaneous photocatalytic H2 evolution with environmental remediation over sem-iconducting metal oxides is a fascinating process for sustainable fuel production. However, most of the previously reported photocatalytic reforming showed nonstoichiometric amounts of the evolved H2 when organic substrates were used. To explain the reasons for this phenomenon, a care-ful analysis of the products and intermediates in gas and aqueous phases upon the photocatalytic hydrogen evolution from oxalic acid using Pt/TiO2 was performed. A quadrupole mass spectrome-ter (QMS) was used for the continuous flow monitoring of the evolved gases, while high performance ion chromatography (HPIC), isotopic labeling, and electron paramagnetic resonance (EPR) were employed to understand the reactions in the solution. The entire consumption of oxalic acid led to a ~30% lower H2 amount than theoretically expected. Due to the contribution of the photo-Kolbe reaction mechanism, a tiny amount of formic acid was produced then disappeared shortly after the complete consumption of oxalic acid. Nevertheless, a much lower concentration of formic acid was generated compared to the nonstoichiometric difference between the formed H2 and the consumed oxalic acid. Isotopic labeling measurements showed that the evolved H2, HD, and/or D2 matched those of the solvent; however, using D2O decreased the reaction rate. Interestingly, the presence of KI as an additional hole scavenger with oxalic acid had a considerable impact on the reaction mechanism, and thus the hydrogen yield, as indicated by the QMS and the EPR measure-ments. The added KI promoted H2 evolution to reach the theoretically predictable amount and in-hibited the formation of intermediates without affecting the oxalic acid degradation rate. The pro-posed mechanism, by which KI boosts the photocatalytic performance, is of great importance in enhancing the overall energy efficiency for hydrogen production via photocatalytic organic reform-ing

Heterogeneous photocatalytic organic synthesis: State-of-the-art and future perspectives

Heterogeneous photocatalytic systems have the potential to provide a green organic synthesis route for a number of industrially important chemicals. Issues remain with lack of selectivity. In this paper, a review is presented on achievements in this field. Parallels are drawn between systems optimised for heterogeneous photocatalytic organic degradation and heterogeneous catalytic organic synthesis. There is much fundamental knowledge that is still missing in this field of research. Parameters that can be manipulated are reaction solvent, pH, photon energy, chosen photocatalyst and its specific properties, and perhaps the use of more than one photocatalyst. Screening of photocatalysts for specific reactions and adapting the reaction conditions may achieve the best selectivity. Unlike the popular case of photocatalysts for organic degradation, the photocatalysts for organic synthesis should be highly customised on a case-by-case basis. Attention should be given to photocatalysts with the potential to be activated by the visible light spectrum, in order to achieve cost effectiveness of the heterogeneous photocatalytic organic synthesis

Heterogeneous photoca talytic organic synthesis: state-of-the-art and future perspectives

Heterogeneous photocatalytic systems have the potential to provide a green organic synthesis route for a number of industrially important chemicals. Issues remain with lack of selectivity. In this paper, a review is presented on achievements in this field. Parallels are drawn between systems optimised for heterogeneous photocatalytic organic degradation and heterogeneous catalytic organic synthesis. There is much fundamental knowledge that is still missing in this field of research. Parameters that can be manipulated are reaction solvent, pH, photon energy, chosen photocatalyst and its specific properties, and perhaps the use of more than one photocatalyst. Screening of photocatalysts for specific reactions and adapting the reaction conditions may achieve the best selectivity. Unlike the popular case of photocatalysts for organic degradation, the photocatalysts for organic synthesis should be highly customised on a case-by-case basis. Attention should be given to photocatalysts with the potential to be activated by the visible light spectrum, in order to achieve cost effectiveness of the heterogeneous photocatalytic organic synthesis.114730Ysciescopu

Exposed aggregate areas and photocatalytic efficiency of photocatalytic aggregate mortar

The authors gratefully acknowledge funding from the UK Engineering and Physical Sciences Research Council (Grant EP/M003299/1) and the Natural Science Foundation of China (Grant 51461135005) International Joint Research Project (EPSRC-NSFC). Thanks are also given to Mr. Anthon Tacussel Da Silva, Mr. Victor Leger, Mr. Robim Campos and Miss Axelle Airmard for their samples preparation and early exploring studies and to Dr. Laszlo Csetenyi for his help in CT scanning.Peer reviewedPostprin

Photocatalytic Functionalized Aggregate : Enhanced Concrete Performance in Environmental Remediation

Funding: This research was funded by the UK Engineering and Physical Sciences Research Council (Grant Ref: EP/M003299/1) and the Natural Science Foundation of China (No. 51461135005) International Joint Research Project (EPSRC-NSFC). The APC was funded by (GORD). Acknowledgments: The authors gratefully acknowledge funding from the UK Engineering and Physical Sciences Research Council (Grant Ref: EP/M003299/1) and the Natural Science Foundation of China (No. 51461135005) International Joint Research Project (EPSRC-NSFC). L. Zheng and M. R. Jones from the Division of Civil Engineering, University of Dundee, Dundee, UK are gratefully acknowledged for the preparation of the mortars.Peer reviewedPublisher PD