01927nas a2200145   4500008004100000022001400041245013900055210006900194260000900263300001400272490000600286520134600292100002401638856011901662       2019                        eng d  a2398-490200aEnhanced light harvesting and charge separation over wormhole mesoporous TiO2-X nanocrystallites towards efficient hydrogen generation0 aEnhanced light harvesting and charge separation over wormhole me  cMAY   a1191-12000 v33 a<p>Here meso-TiO2-X materials with combined visible light absorption, high surface area, an anatase-rutile heterojunction, and electrically interconnected nanocrystallites in a wormhole mesoporous framework are achieved. Meso-TiO2-X materials were prepared by solution combustion synthesis (SCS), followed by hydrogenation at higher temperatures. The materials are thoroughly characterised by various physicochemical techniques. A small band gap (2.8 eV), type IV-H-2 mesoporosity with a biphasic heterojunction, and small pore depths (10 nm) in a wormhole mesoporous framework are observed with 35AP. Photocatalytic water splitting for hydrogen production and photocurrent generation were carried out with meso-TiO2-X materials under simulated sunlight. A six-fold increase in activity under AM 1.5G irradiation was observed, which is attributed to the generated mid-gap states which lead to band gap reduction, improved optical absorption in the visible and infrared light region resulting in higher charge carrier density. The presence of a biphasic heterojunction between the (1 0 1) anatase and (1 1 0) rutile facets assists in effective charge separation. A low charge diffusional constraint associated with wormhole mesoporosity helps in facile charge transport to the surface for improved charge utilisation in redox reactions.</p>
1 aNegi, Sanjay, Singh  uhttps://library.ncl.res.in/content/enhanced-light-harvesting-and-charge-separation-over-wormhole-mesoporous-tio2-x