2D Nanomaterials, with unique structural and electronic features, have shown enormous potential toward photocatalysis fields. However, the photocatalytic behavior of pristine 2D photocatalysts are ...still unsatisfactory, and far below the requirements of practical applications. In this regard, surface defect engineering can serve as an effective means to tune photoelectric parameters of 2D photocatalysts through tailoring the local surface microstructure, electronic structure, and carrier concentration. In this review, recent progress in the design of surface defects with the classified anion vacancy, cation vacancy, vacancy associates, pits, distortions, and disorder on 2D photocatalysts to boost the photocatalytic performance is summarized. The strategies for controlling defects formation and technique to distinguish various surface defects are presented. The crucial roles of surface defects for photocatalysis performance optimization are proposed and advancement of defective 2D photocatalysts toward versatile applications such as water oxidation, hydrogen production, CO2 reduction, nitrogen fixation, organic synthesis, and pollutants removal are discussed. Surface defect modulated 2D photocatalysts thus represent a powerful configuration for further development toward photocatalysis.
Recent progress in the design of surface defects on 2D photocatalysts to boost the photocatalytic performance is summarized. The strategies for controlling defects formation and technique to distinguish various surface defects are presented. The crucial roles of surface defects for photocatalysis performance optimization and advancement of defective 2D photocatalysts toward versatile applications are discussed.
Engineering strong metal-support interactions (SMSI) is an effective strategy for tuning structures and performances of supported metal catalysts but induces poor exposure of active sites. Here, we ...demonstrate a strong metal-support interaction via a reverse route (SMSIR) by starting from the final morphology of SMSI (fully-encapsulated core-shell structure) to obtain the intermediate state with desirable exposure of metal sites. Using core-shell nanoparticles (NPs) as a building block, the Pd-FeO
NPs are transformed into a porous yolk-shell structure along with the formation of SMSIR upon treatment under a reductive atmosphere. The final structure, denoted as Pd-Fe
O
-H, exhibits excellent catalytic performance in semi-hydrogenation of acetylene with 100% conversion and 85.1% selectivity to ethylene at 80 °C. Detailed electron microscopic and spectroscopic experiments coupled with computational modeling demonstrate that the compelling performance stems from the SMSIR, favoring the formation of surface hydrogen on Pd instead of hydride.
•A correlation between the hydrophilic and the adsorption performance of HTO-x was found.•Anatase TiO2-derived LTO-400 showed the highest Li adsorption performance due to its the strongest ...hydrophilic.•HTO-400 presents highly selectivity to Li+ in the presence of cations like Na+ and K+.•LTO-400 exhibits excellent recycling and high stability.
The titanium type lithium ion sieves (LISs) are considered as a promising adsorbent for lithium extraction from liquid resources. However, different TiO2 precursors prepared LISs present greatly difference in adsorption performance and recycle stability. In this study, the influence of the different crystal phases of TiO2 precursors (amorphous, anatase, and rutile) on the adsorption performance of the terminated H2TiO3-lithium ion sieve (HTO) were investigated. On the basis of contact angle experiments, we find the correlation between the hydrophilic and the adsorption performance of HTO. Among the three types of HTO adsorbents, anatase TiO2-derived HTO (HTO-400) exhibited the highest adsorption performance for Li+ due to its the strongest hydrophilicity and was favorable for contacting with Li+ in solution. Lithium adsorption studies showed that the equilibrium adsorption capacity of HTO-400 reached 34.2 mg/g within 24 h. Competitive adsorption and recycling results indicated that HTO-400 possessed a highly selectivity for Li+ and was easy to regeneration.
Taming interfacial electronic effects on Pt nanoparticles modulated by their concomitants has emerged as an intriguing approach to optimize Pt catalytic performance. Here, we report Pt nanoparticles ...assembled on vacancy-abundant hexagonal boron nitride nanosheets and their use as a model catalyst to embrace an interfacial electronic effect on Pt induced by the nanosheets with N-vacancies and B-vacancies for superior CO oxidation catalysis. Experimental results indicate that strong interaction exists between Pt and the vacancies. Bader charge analysis shows that with Pt on B-vacancies, the nanosheets serve as a Lewis acid to accept electrons from Pt, and on the contrary, when Pt sits on N-vacancies, the nanosheets act as a Lewis base for donating electrons to Pt. The overall-electronic effect demonstrates an electron-rich feature of Pt after assembling on hexagonal boron nitride nanosheets. Such an interfacial electronic effect makes Pt favour the adsorption of O
, alleviating CO poisoning and promoting the catalysis.
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•A strong metal-edge interaction (SMEI) was formed between Pt NPs and edges of h-BN.•The SMEI was well characterized and the charge transfer was clarified.•The SMEI induced a promoted ...aerobic oxidative desulfurization activity.•The catalyst showed excellent stability because of the SMSI.
Platinum nanoparticles (Pt NPs) have long been regarded as efficient catalysts for numerous catalytic process, including catalytic oxidation, hydrogenation, etc. For Pt catalysis, tuning the electronic structure for a boosted catalytic performance and exploring a proper strategy for stabilization of the nanoparticles are the two central issues. In this work, we constructed strong metal-edge interactions (SMEI) between well-dispersed Pt NPs and hexagonal boron nitride (h-BN) support. The charge transfer between h-BN and Pt NPs was carefully studied, and it was found that the charge transfers from B atoms in h-BN to Pt NPs and from Pt NPs to N atoms in h-BN. The SMEI makes the Pt NPs positively charged for a boosted aerobic catalytic desulfurization activity with sulfur removals of 98.3%, 96.5%, 93.7% and 85.9% to dibenzothiophene, 4, 6-dimethyldibenzothiophene, 4-methylbenzothiophene, and benzothiophene, respectively. Additionally, the aerobic oxidative desulfurization system showed an excellent resistance performance to olefins and aromatic hydrocarbons. The SMEI also gives rise to an excellent stabilization of the Pt NPs without agglomeration after the reaction. Moreover, the catalyst can be recycled 5 times without a significant decrease in catalytic activity. Additionally, both the geometric structure and the SMEI were well investigated to illuminate the structure-activity relationship.
(A) Before oxidation, (B) during oxidation, (C) after oxidation and (D) catalytic oxidation process of DBT. Display omitted
► POM-based hybrid materials were firstly combined with ionic liquids on ...the removal of DBT. ► The catalyst demonstrated high performance in the deep desulfurization. ► The mechanism and kinetic of oxidation desulfurization process was proposed. ► The structure–activity relationship reactivity of samples was systematically investigated.
A series of POM-based hybrid materials: phosphotungstic acid supported ceria (HPW-CeO2) have been synthesized and characterized by X-ray diffraction (XRD), Thermogravimetric-differential scanning (TG-DSC) analysis, Scanning electron microscopy (SEM), FT-Raman, FT-IR, UV–vis, and BET analysis. Combined with C8mimBF4, the catalyst was very efficient on the removal of DBT by using H2O2 as the oxidant under mild reaction conditions, which could reach a sulfur removal of 99.4%. The amount of catalyst, O/S molar ratio, reaction time and temperatures were evaluated in detail, and the favorable operating condition was obtained as well as the kinetic study of substrates. The structure–activity relationship was systematically investigated. Oxidative desulfurization system could be recycled for ten times without significant decrease in activity. A mechanism was proposed to investigate the oxidation process of DBT.
Tungsten oxide nanoparticles (WOxNPs) are gaining increasing attention, but low stabiliity and poor dispersion of WOxNPs hinder their catalytic applications. Herein, WOxNPs were confined in ...graphene‐analogous boron nitride (g‐BN) by a one‐step, in situ method at high temperature, which can enhance the interactions between WOxNPs and the support and control the sizes of WOxNPs in a range of about 4–5 nm. The as‐prepared catalysts were applied in catalytic oxidation of aromatic sulfur compounds in which they showed high catalytic activity. A balance between the W loading and the size distribution of the WOxNPs could govern the catalytic activity. Furthermore, a synergistic effect between g‐BN and WOxNPs also contributed to high catalytic activity. The reaction mechanism is discussed in detail and the catalytic scope was enlarged.
Solitary confinement: Tungsten oxide nanoparticles (WOxNPs) were confined in graphene‐analogous boron nitride (g‐BN) by a simple, one‐step, in situ method (see picture). WOxNPs anchored through g‐BN show better dispersion and stability, and the sizes of WOxNPs can be controlled in the range of about 4–5 nm. The WOxNPs/g‐BN materials exhibited excellent performance in oxidation of aromatic sulfur compounds and a synergic effect of g‐BN.
•g-BN(x)@SiO2 was synthesized as a packing material for extraction of RhB.•g-BN acted as absorption actives centers, SiO2 acted as carriers.•The spiked recoveries of RhB and R6G was 94.8%–103.1% in ...the real chili powder and beverage samples.
A novel dendritic silicon dioxide nanocomposite coated with a highly dispersed graphene-like boron nitride nanosheet (g-BN(x)@SiO2) was in-situ synthesized and employed as a solid-phase extraction material for the Rhodamine B (RhB) and Rhodamine 6G (R6G) enrichment in food samples prior to their quantitation by HPLC. The structures and morphologies of g-BN(x)@SiO2 were characterized by XRD, FTIR, BET and TEM. The adsorption performance and mechanism were investigated and showed an enhanced maximum adsorption capacity of 625 mg/g for RhB on the nanocomposite loaded with 1% of g-BN via a fast, spontaneous process. Under optimal extraction conditions, this method showed low detection and quantification limits (2.8 μg/L for RhB, 2.1 μg/L for R6G and 9.2 μg/L for RhB, 6.9 μg/L for R6G, respectively), good repeatability (RSD% <3.7%), and satisfactory spiked recoveries of 94.8%–103.1% for RhB and R6G in real chili powder and beverage. Therefore, the g-BN(1%)@SiO2-based materials possess significant potential.
Artificial photosynthesis of valuable chemicals from CO2 is a potential way to achieve sustainable carbon cycle. The CO2 conversion activity is still inhibited by the sluggish charge kinetics and ...poor CO2 activation. Herein, Ag nanoparticles coupled BiOBr have been constructed by in-situ photoreduction strategy. The crafting of interface between Ag nanoparticles and BiOBr nanosheets, achieving an ultra-fast charge transfer. The BiOBr semiconductor excited electrons and plasmonic Ag nanoparticles generated high-energy hot electrons synchronous accelerates the C=O double bond activation. Thus, the optimized Ag/BiOBr-2 heterostructure shows excellent CO2 photoreduction activity with CO production of 133.75 and 6.83 µmol/g under 5 h of 300 W Xe lamp and visible light (λ > 400 nm) irradiation, which is 1.51 and 2.81 folds versus the pristine BiOBr, respectively. The mechanism of CO2 photoreduction was in-depth understood through in-situ FT-IR spectrum and density functional theory calculations. This study provides some new perspectives into efficient photocatalytic CO2 reduction.
Ag/BiOBr heterostructure displays the excellent visible light absorption, ultra-fast charge transfer and enhanced inert C=O double bond activation, thus boosting CO2 photoreduction to CO. Display omitted
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