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Localized surface plasmon resonance (LSPR) has been approved as a distinguished approach to improving the light absorption and carrier migration of photocatalysts. Herein, taking advantage of the LSPR effect of WS2 nanosheets, 1T-WS2/2H-WS2/CdS heterostructures have been constructed for hydrogen production through photocatalytic water splitting. Such heterostructures have strong light absorption ability and excellent photocorrosion resistance. Finite difference time domain (FDTD) simulations demonstrate that the LSPR effect of WS2 nanosheets can improve the photocatalytic performance of 1T-WS2/2H-WS2/CdS heterostructures through photothermal assistance as well as generated hot electrons, and the maximum hydrogen evolution rate of the heterostructures can be further raised to 4.67 mmol g−1 h−1. Significantly, the performance can remain stable in 20 h reaction cycles. This work provides new insight into the design of plasmonic photocatalysts for solar-driven hydrogen evolution. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial water evaporation, a sustainable approach to overcome the global freshwater shortages, requires both robust solar absorber materials and an effective evaporation structure. Herein, tungsten carbide/carbon nanocomposites from a solvent-free synthesis are chosen as the solar absorber materials and uniformly attached on the surface of cotton cloth to construct a water evaporation film. The ultrafine size and good dispersion of tungsten carbide nanoparticles on carbon nanosheets can realize the utilization of the full solar spectrum (200–2500 nm). More importantly, the resultant film exhibits completely different properties on its two sides, where the side with tungsten carbide/carbon nanocomposites is highly hydrophobic and can dispel water vapor and alleviate condensation, while the other side, without any modification, has superhydrophilicity and low thermal-conductivity helpful to re-dissolve salt crystals and prevent heat loss. Thanks to the compatible advantages of tungsten carbide/carbon nanocomposites and cotton cloth, the evaporation rate of the optimal film is 1.58 kg m−2 h−1 under one sun illumination, which can be further raised to 2.53 kg m−2 h−1 if the film is folded into a pyramidal configuration. Significantly, it can retain stable performance through 10 evaporation cycles and is even suitable for considerable evaporation in sewage. We believe this work will provide new insights for the design and fabrication of interfacial water evaporation devices. [ABSTRACT FROM AUTHOR]

Ag/mesoporous black TiO2 nanotubes heterojunctions (Ag‐MBTHs) were fabricated through a surface hydrogenation, wet‐impregnation and photoreduction strategy. The as‐prepared Ag‐MBTHs possess a relatively high specific surface area of ≈85 m2 g−1 and an average pore size of ≈13.2 nm. The Ag‐MBTHs with a narrow band gap of ≈2.63 eV extend the photoresponse from UV to the visible‐light and near‐infrared (NIR) region. They exhibit excellent visible‐NIR‐driven photothermal catalytic and photocatalytic performance for complete conversion of nitro aromatic compounds (100 %) and mineralization of highly toxic phenol (100 %). The enhancement can be attributed to the mesoporous hollow structures increasing the light multi‐refraction, the Ti3+ in frameworks and the surface plasmon resonance (SPR) effect of plasmonic Ag nanoparticles favoring light‐harvesting and spatial separation of photogenerated electron–hole pairs, which is confirmed by transient fluorescence. The fabrication of this SPR‐enhanced visible‐NIR‐driven Ag‐MBTHs catalyst may provide new insights for designing other high‐performance heterojunctions as photocatalytic and photothermal catalytic nanomaterials. Responding strongly: Ag/mesoporous black TiO2 hollow nanotube heterojunctions with wide‐spectrum response (≈2500 nm) were fabricated through a wet‐impregnation and photoreduction strategy. They exhibit excellent visible‐NIR‐driven photocatalytic and photothermal catalytic performance and long‐term stability, due to the synergistic effect of efficient surface hydrogenation, hollow structured TiO2, formation of heterojunctions, and surface plasmon resonance of Ag. [ABSTRACT FROM AUTHOR]

It is desirable to develop an efficient visible-light-driven photocatalyst for practical application to degrade highly-noxious pollutants. Herein, the hydrogenation hierarchical flower-like Bi 2 MoO 6 hollow spheres (H-BMO-X, where X represents the different hydrogen calcination temperatures) have been successfully fabricated by a solvothermal-surface hydrogenation process. The as-prepared nano-photocatalyst H-BMO-300 clearly exhibits a photocatalytic reaction apparent rate constant k for high-noxious pollutants by ∼3-times higher than pristine Bi 2 MoO 6 . Moreover, the resultant H-BMO-300 sample with a narrow bandgap of ∼2.70 eV possesses surface oxygen vacancy defects. Based on the scanning Kelvin probe and surface photovoltage spectroscopy, it is deduced that the photocatalytic activities are attributed to the surface oxygen vacancy of H-BMO-X favoring the electron-hole pair’s separation. The enhanced photocatalytic performance can be ascribed to the synergistic effect of surface defects favoring efficient electron-hole separation and the hollow hierarchical structure benefiting the utilization of visible light, which provides more surface-active sites. This work provides a viable route to perceptibly enhance the photocatalytic activities of H-BMO-300 for environmental remediation with good mineralization properties. [ABSTRACT FROM AUTHOR]

Uniform black TiO2 nanothorns/graphene/black TiO2 nanothorns sandwichlike nanosheets (denoted as G@BTN) are fabricated through facile solvothermal approach and subsequent surface hydrogenation, in which the black TiO2 nanothorns vertically grow on the surface of two sides of graphene and form the sandwichlike structure. The rational control of hydrolysis and condensation of Ti precursors results in a uniform coating of amorphous TiO2 seeds, which then vertically grow in TiO2 nanothorns. After surface hydrogenation, the resultant G@BTN materials, with uniform sandwichlike configuration and narrow band gap of approximately 2.81 eV, can extend the photoresponse from the ultraviolet to the visible-light region and exhibit an excellent solar-driven photocatalytic performance for the degradation of the highly toxic pesticide atrazine (99 %). The first-order rate constant ( k) of G@BTN (0.863 h−1) is about three times as high as that of black TiO2 nanothorns (0.287 h−1), which implies the significant role of the introduction of graphene for improving the photocatalytic performance. The high solar-driven photocatalytic performance is ascribed to the formed Ti3+ in frameworks and surface disorders enhancing the absorption of solar light, and the sandwichlike structure favoring the separation and transportation of photogenerated charge carriers. [ABSTRACT FROM AUTHOR]

Environmentally friendly catalysts with excellent performance and low cost are critical for photocatalysis. Herein, using hydrogenated TiO 2 (h-TiO 2 ) nanosheets with enriched oxygen vacancies as the support, two-dimensional CoO/h-TiO 2 Z-scheme heterostructures are fabricated for hydrogen production through photocatalytic water splitting. It is revealed that the oxygen vacancies in h-TiO 2 can inhibit the oxidation of Co 2+ into high-valence Co 3+ during the hydrothermal reaction and thermal treatment processes. A CoO/h-TiO 2 Z-scheme heterostructure possesses a space charge region and a built-in electric field at the interface, and oxygen vacancies in h-TiO 2 can provide more reactive sites, which synergistically improve the separation and transportation of photogenerated carriers. As a result, the photocatalytic hydrogen evolution rate achieves 129.75 μmol·h -1 (with 50 mg of photocatalysts) on the optimized CoO/h-TiO 2 heterostructures. This work provides a new design idea for the preparation of excellent TiO 2 -based photocatalysts.

Defective ZnIn 2 S 4 nanosheets/mesoporous black TiO 2 heterojunction hollow spheres (H-ZIS/b-TiO 2 ) are prepared through hydrothermal and surface low-temperature hydrogenation strategies, which show broad-spectrum response and excellent charge separation efficiency. This H-ZIS/b-TiO 2 flower-like heterojunction hollow spheres with a narrow band gap of ∼1.88 eV expand the light response to visible light and show excellent photocatalytic hydrogen evolution rate (278 μmol h -1 50 mg -1 ) under visible-light irradiation, which is 1.5 times as high as that of ZnIn 2 S 4 /black TiO 2 heterojunction hollow spheres (ZIS/b-TiO 2 ) (181 μmol h -1 50 mg -1 ). The excellent photocatalytic performance is due to the formation of O, S dual vacancies in b-TiO 2 and H-ZIS providing more active sites for photocatalytic reaction and improving the charge separation efficiency, heterojunctions promoting transport of photogenerated carriers, and the hollow structure increasing light utilization by reflecting light. The novel heterojunction hollow sphere with high performance has broad application prospects in the field of energy.

Metal-free heterogeneous catalysts are receiving more and more attention for wastewater remediation by activating peroxymonosulfate (PMS) due to their environmental benign. However, carbon-based materials as the most typical metal-free heterogeneous always suffer from poor durability. Inspired by the fact that a conjugated system may facilitate the electron transfer during PMS activation, we innovatively select polyaniline (PANI) as a new PMS activator and investigate its catalytic performance in detail. It is found that PANI can display better catalytic performance than traditional metal-based catalysts and popular N-doped carbocatalysts in methyl orange (MO) degradation. More importantly, PANI is not only universal for various pollutants degradation but also maintains its catalytic performance in repeated degradation experiments. The stable N sites in the conjugated chains and the oxidation-resistance benzene rings as the building units are considered to be responsible for such an excellent durability. In addition, the influences of some routine factors and actual water backgrounds are comprehensively checked and analyzed. The quenching experiments and electron paramagnetic resonance confirm that MO degradation is achieved through both radical and nonradical pathways, where SO 4 •- and 1 O 2 are primary reactive species. The reaction mechanism is also proposed with the assistance of X-ray photoelectron spectroscopy.

NiS nanoparticles modified black TiO 2 hollow nanotubes (NBTNs) are successfully synthesized via surface hydrogenation and the facile solvothermal method. The unique structure with intensified surface and interface characteristics endow NBTNs with more catalytic sites, and increase charge carrier separation efficiency with an extended charge lifetime, overwhelmingly promoting its photocatalytic performance. The resultant NBTNs possess a relatively high surface area and pore size of ∼89 m 2 g -1 and ∼9.8 nm, respectively. The resultant NBTNs exhibit an excellent solar-driven photocatalytic hydrogen rate (3.17 mmol h -1 g -1 ), which is almost as high as that of Pt as cocatalyst, in which the apparent quantum yield of 5.4% (420 nm) is recorded for the NBTNs sample. Moreover, the turnover number can be up to 116 000 within 48 h and the turnover frequency is 2400 for NiS. This novel strategy could provide a better understanding of cocatalyst photocatalytic mechanisms, and a scheme simultaneously regulating the morphology and structure of photocatalysts for promoting H 2 generation.

The photocatalytic hydrogen evolution of TiO 2 is deemed to be one of the most promising ways of converting solar energy to chemical energy; however, it is a challenge to improve the photo-generated charge separation efficiency and enhance solar utilization. Herein, black mesoporous rutile/anatase TiO 2 microspheres with a homojunction and surface defects have been successfully synthesized by an evaporation-induced self-assembly, solvothermal and high-temperature surface hydrogenation method. The H500-BMR/ATM (H X -BMR/ATM, where X means the different hydrogen calcination temperatures) materials not only possess a mesoporous structure and relatively high specific surface area of 39.2 m 2 g -1 , but also have a narrow bandgap (∼2.87 eV), which could extend the photoresponse to the visible light region. They exhibit high photocatalytic hydrogen production (6.4 mmol h -1 g -1 ), which is much higher (approximately 1.8 times) than that of pristine mesoporous rutile/anatase TiO 2 microspheres (3.58 mmol h -1 g -1 ). This enhanced photocatalytic hydrogen production property is attributed to the synergistic effect of the homojunction and surface defects in improving efficient electron-hole separation and high utilization of solar light. This work proposes a new approach to improve the performance of photocatalytic hydrogen production and probably offers a new insight into fabricating other high-performance photocatalysts., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Ag/mesoporous black TiO 2 nanotubes heterojunctions (Ag-MBTHs) were fabricated through a surface hydrogenation, wet-impregnation and photoreduction strategy. The as-prepared Ag-MBTHs possess a relatively high specific surface area of ≈85 m 2  g -1 and an average pore size of ≈13.2 nm. The Ag-MBTHs with a narrow band gap of ≈2.63 eV extend the photoresponse from UV to the visible-light and near-infrared (NIR) region. They exhibit excellent visible-NIR-driven photothermal catalytic and photocatalytic performance for complete conversion of nitro aromatic compounds (100 %) and mineralization of highly toxic phenol (100 %). The enhancement can be attributed to the mesoporous hollow structures increasing the light multi-refraction, the Ti 3+ in frameworks and the surface plasmon resonance (SPR) effect of plasmonic Ag nanoparticles favoring light-harvesting and spatial separation of photogenerated electron-hole pairs, which is confirmed by transient fluorescence. The fabrication of this SPR-enhanced visible-NIR-driven Ag-MBTHs catalyst may provide new insights for designing other high-performance heterojunctions as photocatalytic and photothermal catalytic nanomaterials., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)