Photocatalytic hydrogen generation by WO3 in synergism with hematite-anatase heterojunction

Efficient Photocatalytic Charge Separation at Anatase–Hematite Heterojunctions with a Tuned Three-Dimensional Cocatalytic NiO Support

“…This alteration in NiO peak intensities further confirm the formation of the Fe 2 O 3 -TiO 2 @NiO heterostructure. The diffraction peaks observed between 20 and 60° in the enlarged XRD pattern (Figure B) indicate the existence of anatase TiO 2 and hematite Fe 2 O 3 in the modified material. ,,, Among the ternary heterostructures, the characteristic peaks observed at 2θ = 35.4 and 49.2° correspond to the (110) and (024) planes of rhombohedral hematite Fe 2 O 3 (JCPDS 33-0664) and at 2θ = 25.3 and 49.2°correspond to (101) and (105) planes of anatase TiO 2 . ,,, Also, these observed peaks are of appreciable intensity in the Fe 2 O 3 -TiO 2 @2%NiO. Hence, the three-dimensional ternary Fe 2 O 3 -TiO 2 @2%NiO heterostructure is expected to show an enhanced photocatalytic activity toward hydrogen generation.…”

“…7 eV correspond to Ni 2p 3/2 and its satellite. ,, The four peaks thus observed for Ni 2p could be attributed to the presence of Ni 2+ , revealing the presence of NiO. , Furthermore, the deconvoluted spectra of O 1s (Figure e) exhibit three peaks. The peaks observed at 530.9, 532.7, and 534.5 eV correspond to the lattice O 2– species, −OH, and adsorbed H 2 O. ,,− Precisely, herein, O is characteristic of the metal-oxygen bonds. However, a relatively higher peak corresponding to the −OH bond of the NiO cocatalyst of the Fe 2 O 3 -TiO 2 @2%NiO is observed.…”

“…Over the past decades, various semiconductor systems including TiO 2 , ZnO, BiVO 4 , Fe 2 O 3 , CdS, Cu 2 O, and so forth have been applied for the construction of heterostructures. − Among them, Fe 2 O 3 -based photocatalytic systems have gained substantial attention owing to their favorable band gap characteristics, nontoxicity, low cost, and high stability . Our research group has previously reported different modifications and hybrids of iron/titanium-based photocatalytic systems via heterojunction engineering to enhance the redox reaction capability and charge separation efficiency. − However, it is mostly difficult for such hybrid systems to confirm the stability of cocatalysts employed, so that the overall performance and photocatalytic stability unveil much certain limitations.…”

Doping regulates pyro-photo-electric catalysis to achieve efficient water splitting in Ba1−xSrxTiO3 through solar energy and thermal resources

“…The exact value of illumination intensity measured by irradiometer is 93.1 mW·cm −2 . All curves show positive values under 260–400 nm illumination, because the band bending on the n-type semiconductor surface points upwards, thus forming a built-in electric field from the bulk phase to the surface 47 , and the holes flow to the surface under the action of the built-in electric field. The temperature change also adjusts the built-in electric field, enhancing the separation of carriers and leading to a higher surface photovoltage.…”

Enhancement of biological hydrogen production from organic wastes with the application of nanomaterials

“…The nanomaterials such as TiO 2 , CdS, and SiC are clean, cheap, and show better photocatalytic properties thereby it can be applied to produce photocatalytic hydrogen production 42‐44 . At present, various nanomaterials such as ZnO, 45 Ta 2 O 5 , 46 α‐Fe 2 O 3 , 47 Nb 2 O 5 , 48 TaON, 49 BiVO 4 , 50 and WO 3 51 have been explored. Band gap is a key issue in most of photocatalysts that results in lower production of hydrogen.…”