02432nas a2200265   4500008004100000245014900041210006900190260000800259300000900267490000800276520151200284653002801796653002401824653001401848653001901862653002201881653002201903100002001925700001701945700001701962700001601979700003001995700001802025856012302043       2017                        eng d00aBand alignment and charge transfer pathway in three phase anatase-rutile-brookite TiO2 nanotubes: an efficient photocatalyst for water splitting0 aBand alignment and charge transfer pathway in three phase anatas  cDEC  a9-190 v1283 aThe study reports electrochemical synthesis, phase evolution and hydrogen generation efficiency of anatase, anatase-rutile and anatase-rutile-brookite (ARB) TiO2 nanotubes for the first time. The SEM and TEM micrographs confirm the tubular morphology of the samples. The presence of anatase, rutile and brookite phases in a single nanotube is confirmed from high resolution TEM analysis. The water splitting efficiency of the three systems are studied under one sun illumination. It is observed that the anatase-rutile-brookite TiO2 nanotubes are highly efficient compared to anatase-rutile or anatase TiO2 nanotubes. The hydrogen generated by ARB composites, after four hours of one sun illumination, is found to be nearly twice that of anatase TiO2 nanotubes and 1.6 times that of anatase-rutile TiO2 nanotubes. The results suggest that the ARB in single nanotube having two junction interfaces, highly facilitate interparticle charge transfer compared to single junction anatase-rutile or bare anatase TiO2 nanotubes. From the deconvolution of PL spectra and the synchrotron radiation assisted valence band edge analysis, the band diagram for the anatase-rutile-brookite phase is constructed. The charge separation and its transfer pathway for efficient photo-assisted water splitting are delineated. This opens a new route for the simple synthesis and study of tri-phase TiO2 for efficient photocatalytic water splitting compared to the widely studied two phase TiO2. (C) 2017 Published by Elsevier B.V.10aAnatase-Rutile-Brookite10aHydrogen generation10ananotubes10aPhotocatalysis10aphotoluminescence10aValence band edge1 aPreethi, L., K.1 aMathews, Tom1 aNand, Mangla1 aJha, S., N.1 aChinnakonda, Gopinath, S.1 aDash, Sitaram  uhttps://library.ncl.res.in/content/band-alignment-and-charge-transfer-pathway-three-phase-anatase-rutile-brookite-tio202124nas a2200181   4500008004100000245010700041210006900148260000800217300002600225490000600251520144700257100002001704700002301724700001701747700002001764700003001784856012801814       2017                        eng d00aStudy on doped heterojunctions in TiO2 nanotubes: an efficient photocatalyst for solar water splitting0 aStudy on doped heterojunctions in TiO2 nanotubes an efficient ph  cOCT  aArticle Number: 143140 v73 aThe two important factors that affect sunlight assisted water splitting ability of TiO2 are its charge recombination and large band gap. We report the first demonstration of nitrogen doped triphase (anatase-rutile-brookite) TiO2 nanotubes as sun light active photocatalyst for water splitting with high quantum efficiency. Nitrogen doped triphase TiO2 nanotubes, corresponding to different nitrogen concentrations, are synthesized electrochemically. Increase in nitrogen concentration in triphase TiO2 nanotubes is found to induce brookite to anatase phase transformation. The variation in density of intra-band states (Ti3+ and N 2p states) with increase in nitrogen doping are found to be critical in tuning the photocatalytic activity of TiO2 nanotubes. The presence of bulk heterojunctions in single nanotube of different nitrogen doped TiO2 samples is confirmed from HRTEM analysis. The most active nitrogen doped triphase TiO2 nanotubes are found to be 12 times efficient compared to pristine triphase TiO2, for solar hydrogen generation. The band alignment and charge transfer pathways in nitrogen doped TiO2 with triphase heterojunctions are delineated. Bulk heterojunctions among the three phases present in the nanotubes with intra-band defect states is shown to enhance the photocatalytic activity tremendously. Our study also confirms the theory that three phase system is efficient in photocatalysis compared to two phase system.1 aPreethi, L., K.1 aAntony, Rajini, P.1 aMathews, Tom1 aWalczak, Lukasz1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/study-doped-heterojunctions-tio2-nanotubes-efficient-photocatalyst-solar-water-splitting