Photo-depositing Ru and RuO2 on Anatase TiO2 Nanosheets as Co-catalysts for Photocatalytic O2 Evolution from Water Oxidation

TiO2 nanosheets mainly exposed （001） facet were prepared through a hydrothermal process with HF as the morphology-directing agent. Ru and RuO2 species were loaded by photo-deposition methods to prepare the photocatalysts. The structural features of the catalysts were characterized by X-ray di raction, transmission electron microscopy, inductively cou-pled plasma atomic emission spectrum, and H2 Temperature-programmed reduction. The photocatalytic property was studied by the O2 evolution from water oxidation, which was examined with respect to the in uences of Ru contents as well as the oxidation and reduction treatments, suggesting the charge separation effect of the Ru species co-catalysts on di erent facets of TiO2 nanosheets. In contrast to Ru/TiO2 and RuO2/TiO2 with the single deposited co-catalyst, the optimized catalyst 0.5%Ru-1.0%RuO2/TiO2 with dual co-catalysts achieved a much improved catalytic performance, in terms of the synergetic effect of dual co-catalysts and the enhanced charge separation effect.

Carbon and few-layer MoS2 nanosheets co-modified TiO2 nanosheets with enhanced electrochemical properties for lithium storage

Carbon and few-layer MoS2 nanosheets co- modified TiO2 nanocomposites （defined as MoS2-C@TiO2） were prepared through a facile one-step pyrolysis reaction technique. In this unique nanostructure, the TiO2 nanosh- eets with stable structure serve as the backbones, and carbon coating and few-layer MoS2 tightly adhere onto the surface of the TiO2. It needs to be pointed out that the carbon coating improves the overall electronic conductivity and the few-layer MoS2 facilitates the diffusion of lithium ions and offers more active sites for lithium-ion storage. As a result, when evaluated as lithium-ion battery anodes, the MoS2-C@TiO2 nanocomposites exhibit markedly enhanced lithium storage capability compared with pure TiO2. A high specific capacity of 180 mA.h.g-1 has been achieved during the preliminary cycles, and the specific capacity can maintain 160 mA.h.g-1 at a high current density of 1C （1C=167 mA.g-1） even after 300 discharge/ charge cycles, indicating the great potential of the MoS2- C@TiO2 on energy storage.

Surface-adsorbed ions on TiO2 nanosheets for selective photocatalytic CO2 reduction

A method based on the adsorption of ions on the surface of two-dimensional （2D） nanosheets has been developed for photocatalytic COz reduction. Isolated Bi ions, confined on the surface of TiO2 nanosheets using a simple ionic adsorption method facilitate the formation of a built-in electric field that effectively promotes charge carrier separation. This leads to an improved performance of the photocatalytic COa reduction process with the preferred conversion to CH4. The proposed surface ion-adsorption method is expected to provide an effective approach for the design of highly efficient photocatalytic systems. These findings could be very valuable in photocatalytic CO2 reduction applications.

Photocatalytic H2 Evolution on TiO2 Assembled with Ti3C2 MXene and Metallic 1T-WS2 as Co-catalysts

The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst’s surface.In this paper,we report that double metallic co-catalysts Ti3C2 MXene and metallic octahedral(1T)phase tungsten disulfide(WS2)act pathways transferring photoexcited electrons in assisting the photocatalytic H2 evolution.TiO2 nanosheets were in situ grown on highly conductive Ti3C2 MXenes and 1T-WS2 nanoparticles were then uniformly distributed on TiO2@Ti3C2 composite.Thus,a distinctive 1T-WS2@TiO2@Ti3C2 composite with double metallic co-catalysts was achieved,and the content of 1T phase reaches 73%.The photocatalytic H2 evolution performance of 1T-WS2@TiO2@Ti3C2 composite with an optimized 15 wt%WS2 ratio is nearly 50 times higher than that of TiO2 nanosheets because of conductive Ti3C2 MXene and 1T-WS2 resulting in the increase of electron transfer efficiency.Besides,the 1T-WS2 on the surface of TiO2@Ti3C2 composite enhances the Brunauer–Emmett–Teller surface area and boosts the density of active site.

Enhancing photocatalytic performance by constructing ultrafine TiO2 nanorods/g-C3N4 nanosheets heterojunction for water treatment

Photocatalysis is considered to be a clean, green and efficient method to purify water. In this report, we first developed a highly efficient ultrafine TiO2 nanorods/g-C3N4 nanosheets （TiO2 NR/CN NS） composites via a simple hydrothermal method. Tiny TiO2 nanorods （diameter： ～1.5 nm and length： ～8.3 nm） were first loaded in situ on the CN NS by adding graphitic carbon nitride （g-C3N4） to the reaction solution. The TiO2 NR/CN NS composites present high charge separation efficiency and broader light absorbance than P25 TiO2. Furthermore, we illustrate that the TiO2 NR/CN NS catalyst possesses high performance for the photocatalytic degradation of the common and stubborn pollutants in water, such as the rhodamine B （RhB） dye and phenol. Under visible light （λ 〉 420 nm） irradiation, the apparent rate of the TiO2 NR/CN NR is 172 and 41 times higher than that of the P25 TiO2 and TiO2 NR, respectively. Additionally, we speculated that the heterojunction formed between TiO2 NR and CN NS, which is the basis for the experiments we have designed and the corresponding results. We demonstrated that reactive oxidative species such as superoxide anion radical and holes play critical roles in the degradation, and the hydroxyl radical contributes nothing to the degradation.

Synthesis and characterization of anatase TiO_2 nanosheet arrays on FTO substrate

We have exploited a green approach to prepare layered titanate Na2_xHxTi2Os-H20 nanosheet arrays on FFO substrate by hydrothermal hydrolysis of titanium（IV） isopropoxide （TRIP） with aids of Na2EDTA and TEOA as co-coordination agents, which were then treated by HNO3 to replace Na＋ by H＋, followed by a calcination at 450℃ to topotactically transform into anatase TiO2 nanosheet arrays. SEM, TEM, XRD, and Raman spectroscopy have been employed to characterize the nanosheet films. The TiO2 nanosheet arrays were further applied as electron transport materials of CH3NH3PbI3 perovskite solar cells, achieving power conversion efficiency of 6.99%.

Z型电荷分离介导的0D/2D AgVO_(3)/TiO_(2)异质结用于增强光催化CO_(2)还原

合理利用Z型电荷调节机制是提高光催化CO_(2)还原效率的有效策略.在本工作中,通过将AgVO_(3)量子点(QDs)原位锚定在TiO_(2)纳米片(NSs)上,从而构建了0D/2D AgVO_(3)/TiO_(2)直接Z型异质结光催化剂.TiO_(2)NSs抑制了AgVO_(3)量子点自身的团聚,从而优化了体系的形貌结构.AgVO_(3)QDs增强了复合材料的光吸收能力,从而提高了对太阳光的利用效率.同时,两种单体之间匹配的能带结构和合适的内部界面电场(即(-)AgVO_(3)/(+)TiO_(2))促进了直接Z型异质结的构建,从而显著促进了光生电子-空穴对的分离,并保持了体系中最高的氧化还原电位.优化后的AgVO_(3)/TiO_(2)复合材料在没有任何助催化剂的情况下,表现出具有竞争力的光催化CO_(2)还原效率(CO,47.61μmol h-1g-1),是原始TiO_(2)NSs的20.97倍.本工作提出了一种直接Z型异质结的合理设计方法,为高效光催化CO_(2)还原催化剂的开发提供了指导.