Recently, the photocatalytic CO2 reduction technology is an effective solution to remit the energy crisis. Inorder to improve the photocatalytic performance, Z-scheme W18O49/NiAl-LDH composite ...catalysts wereprepared by hydrothermal method. Fortunately, the prepared catalysts revealed excellent photocatalyticperformance under the simulated sunlight, and CO and CH4 could be detected in the reduction products.
WO/LDH-0.5 catalyst possessed the optimal activity, with CO and CH4 yield of 37.09 and 8.01 lmol g-1h1separately, which were 7.9 and 3.6 times that of NiAl-LDH monomer. In addition, W18O49 endowedW18O49/NiAl-LDH catalysts with photothermal effect, which raised the surface temperature andfacilitated the catalytic reaction. Meanwhile, the Z-scheme heterojunction composed of flower-likeNiAl-LDH and urchin-like W18O49 accelerated the separation of photoexcited carriers and enhanced theredox ability. Through a series of characterizations and investigations, this work is promising to breaknew ground for the design of photocatalysts with photothermal effect. KCI Citation Count: 0
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•The CoAl-LDH/CGCNN-Metal NPs ternary photocatalysts with visible light response were prepared.•CoAl-LDH/CGCNN-Au NPs could convert CO2 into CO, CH4, C2H4, and C2H6 with the yields of ...5.93, 17.68, 1.25 and 2.15 µmol g−1h−1.•The synergistic effect between S-scheme heterojunction and metal NPs could improve the light absorption capacity and the separation of photogenerated electron-hole pairs.
Converting CO2 into high-value products by photocatalysis can alleviate the global greenhouse effect and energy crisis. In this work, CoAl-LDH/CGCNN-Metal NPs (AC-M) ternary photocatalysts were synthesized by calcination, hydrothermal, and ultrasonic self-assembly methods. In pure water, the best sample AC-Au could convert CO2 into CO, CH4, C2H4, and C2H6 with the yields of 5.93, 17.68, 1.25 and 2.15 µmol g−1h−1, respectively, and exhibited good stability within 5 cycles (30 h). The synergistic effect between S-scheme heterojunction and metal NPs could broaden the composite's photo-response range and promote the separation of photogenerated carriers. Furthermore, the metal NPs could also serve as the electron-rich centers to improve the chemisorption of CO2 and convert it into C1 and C2 products under visible light. This work can provide meaningful guidance for studying the efficient reduction of CO2 to C1 and C2 products by S-scheme heterojunction/metal NPs ternary photocatalytic system.
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•Mn–Sb/TiO2 catalyst shows higher NH3-SCR activity and wider temperature window than Mn/TiO2 catalyst.•Mn–Sb/TiO2 catalyst has much better Na-resistance than Mn/TiO2 catalyst.•The ...addition of Sb on Mn/TiO2 catalyst can improve its low-temperature reducibility.•The addition of Sb on Mn/TiO2 catalyst can generate strong Lewis acid sites for NH3 adsorption.
Na has a serious deactivation effect on Mn/TiO2 catalyst for selective catalytic reduction of NO with NH3. In this study, it was found that Sb had a promotion effect on the Na resistance of MnOx/TiO2 catalyst. Then the promotion mechanism was investigated based on the characterization results of BET, XRD, H2-TPR, NH3-TPD, XPS and in situ DRIFT. The results of H2-TPR and NH3-TPD showed that the addition of Sb on MnOx/TiO2 could enhance the redox ability and surface acidity respectively, and the results of DRIFT indicated that the addition of Sb on MnOx/TiO2 could generate strong Lewis acid sites on the catalyst surface for NH3 adsorption. Therefore, the doping of Sb has a promotion effect on the Na resistance of Mn/TiO2 catalyst.
The photocatalytic CO2 reduction technology can effectively decrease the CO2 content in air while converting CO2 into high-value-added chemicals and turning waste into treasure. In this study, Cu2O ...with a concave cubic structure was fabricated by selective etching, and ZnIn2S4 nanosheets were successfully loaded on it uniformly, which significantly elevated its catalytic activity. The maximum CO yield of 9.98 μmol/g/h was obtained on the Z-scheme ZIS/Cu2O-0.3 photocatalyst, which was 3.7 and 4.3 times as high as the bare Cu2O concave cube and ZnIn2S4, respectively. The excellent photocatalytic performance could be attributed to the construction of Z-scheme heterojunction which facilitated the efficient separation of electron–hole pairs, a large specific surface area that provided an abundance of reactive sites, and positive visible light response.
A sequence of Cr-modified CeZr2Ox catalysts were synthesized through the co-precipitation way and applied in selective catalytic reduction (SCR) of NOx with ammonia. The optimal catalyst (Cr1CeZr2Ox) ...exhibited the excellent NH3-SCR activity and high SO2 resistance. From the characterization results, Cr species in Cr1CeZr2Ox could suppress the formation of ZrO2 crystals, which could also contribute to stronger surface acidity and reducibility. Besides, more Ce3+ and surface adsorbed oxygen species were observed on Cr1CeZr2Ox catalyst. On the basis of in situ DRIFT experiments, it could be confirmed that the NH3-SCR process on Cr1CeZr2Ox was promoted through Langmuir-Hinshelwood (L-H) mechanism. Besides, the improved NO oxidation and more ad-NOx and ad-NH3 also played a vital role for the superior low-temperature SCR activity of Cr1CeZr2Ox.
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•Cr1CeZr2Ox catalyst shows higher SCR activity and SO2 tolerance.•The addition of Cr on CeZr2Ox catalyst could generate more ad-reactants.•Cr in CeZr2Ox catalyst could improve the reactivities of ad-reactants.
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•MnSbTiOx-0.2 catalyst shows higher SCR activity and better SO2 resistance than MnTiOx catalyst.•The addition of Sb on MnTiOx catalyst could improve the adsorption of NH3 and NOx ...species.•The SCR reaction over MnSbTiOx-0.2 catalyst is mainly accelerated via L-H route.
Sb was used as the additive to enhance the NH3-SCR performance of MnTiOx catalyst. Experimental results revealed that MnSbTiOx-0.2 demonstrated outstanding NH3-SCR activity in a wide temperature window (100–400 ℃) and high resistance to SO2. Characterization results indicated the introduction of Sb into MnTiOx catalyst could improve the dispersity of active species and generate more surface acid sites, Mn4+ and surface adsorbed oxygen species. In situ DRIFT spectra proved that the presence of Sb in MnSbTiOx-0.2 catalyst could form new Brønsted acid sites, along with the increased surface Lewis acidity. The improved adsorption of NH3 and NOx species over MnSbTiOx-0.2 catalyst had a stimulating effect on the NH3-SCR reaction over it through Langmuir−Hinshelwood (L-H) route. Moreover, Sb species in MnSbTiOx-0.2 could improve the reactivities of ad-NH3 and ad-NOx species in SCR reaction. All these factors contributed to the excellent performance of MnSbTiOx-0.2 catalyst.
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•CsxWO3/g-C3N4 catalyst shows full spectrum CO2 photoreduction activity.•Improved charge separation efficiency is realized on CsxWO3/g-C3N4 catalyst.•LSPR effect is responsible for ...the NIR photocatalytic activity.
Full spectrum-driven CsxWO3/g-C3N4 catalyst was successfully synthesized by the combination of solvothermal and ultrasonication methods and used in CO2 photocatalytic reduction. The experimental results suggested that 20 wt% CsxWO3/g-C3N4 catalyst possessed the best yield of CH4 under NIR and full spectrum light irradiation, which were 1.72 and 6.79 μmol·g−1·h−1, respectively. This outstanding photocatalytic activity could be attributed to the localized surface plasmonic resonance effect and the formation of heterojunction structure, which led to the improved charge separation efficiency, good light-harvesting ability and broadened light response.
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•The introduction of HCl generates more Brønsted acid sites and improves surface acidity of the CeMo catalyst.•Poisoning the CeMo-Na catalyst with HCl could enhance its SCR ...performance due to the offsetting effect of Na&HCl.•The SCR reactions over the samples all follow both the E-R and L-H reaction mechanisms.
This work mainly illustrated the synergistic effects of Na and HCl on the SCR performance of CeMo catalysts. Given that the fresh CeMo catalyst was treated with HCl or doped by Na, the weakened acidity and oxidizability would interfere with the adsorption and activation of NH3, thus resulting in a downward trend of the catalyst deNOx performance. Notably, for the HCl treated Na-poisoned catalyst, the treatment with HCl introduced additional acid sites onto the Na-poisoned catalyst surface and increased the availability of Ce4+ and chemisorbed oxygen. These behaviors exerted a certain promotional effect on the adsorption and activation of NH3. Apparently, the catalyst's deNOx performance slightly rebounded, suggesting the offsetting effects of HCl. Such knowledge would be vital to the stable operation in real coal-fired flue gas.
The transdermal administration of chemotherapeutic agents is a persistent challenge for tumor treatments. A model anticancer agent, epirubicin (EPI), is attached to functionalized superparamagnetic ...iron‐oxide nanoparticles (SPION). The covalent modification of the SPION results in EPI–SPION, a potential drug delivery vector that uses magnetism for the targeted transdermal chemotherapy of skin tumors. The spherical EPI–SPION composite exhibits excellent magnetic responsiveness with a saturation magnetization intensity of 77.8 emu g−1. They feature specific pH‐sensitive drug release, targeting the acidic microenvironment typical in common tumor tissues or endosomes/lysosomes. Cellular uptake studies using human keratinocyte HaCaT cells and melanoma WM266 cells demonstrate that SPION have good biocompatibility. After conjugation with EPI, the nanoparticles can inhibit WM266 cell proliferation; its inhibitory effect on tumor proliferation is determined to be dose‐dependent. In vitro transdermal studies demonstrate that the EPI–SPION composites can penetrate deep inside the skin driven by an external magnetic field. The magnetic‐field‐assisted SPION transdermal vector can circumvent the stratum corneum via follicular pathways. The study indicates the potential of a SPION‐based vector for feasible transdermal therapy of skin cancer.
As a novel transdermal anticancer agent, epirubicin‐loaded superparamagnetic iron oxide nanoparticles (EPI–SPION) exhibit excellent magnetic responsiveness, a pH‐sensitive release profile, and biocompatibility. The EPI–SPION composites, driven by magnetic force, can penetrate the human dermis stratum readily via a transfollicular pathway, which follows an alternative strategy for skin cancer treatment by using superparamagentic nanomaterials.
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•Pr-modified MnCeOx catalysts exhibited excellent SCR performance and SO2 tolerance.•The SCR reaction pathways based on both L-H and E-R mechanisms were investigated.•The ad-NH3 ...species on MnCePrOx-0.3 showed superior reactivity.•Abundant of Oads and Mn4+ on MnCePrOx-0.3 catalysts promoted the “fast SCR”.
Using a one-step impregnation method, a series of Pr-modified MnCeOx catalysts with different Pr molar ratios were created to manufacture an efficient and effective catalyst for low-temperature NH3-SCR. It was demonstrated that the Pr modification could extensively boost the MnCeOx catalysts’ de-NOx activity and SO2 resistance and led to the formation of a unique broom-like morphology, especially when the molar ratio of Pr/Mn = 0.3, the MnCePrOx-0.3 exhibited above 90 % NO conversion at 250 °C with the existence of 100 ppm SO2. According to the characterization results, the enhancement of Pr doping for MnCeOx catalysts was mainly manifested by the expanded specific surface area, the improved dispersion of active components, the enhanced surface acidity and redox ability, and the generated more chemisorbed oxygen (Oads) species. All these characteristics allowed the NH3-SCR reaction over MnCePrOx-0.3 catalysts to proceed through the both Eley-Rideal (E-R) and Langmuir-hinshelwood (L-H) mechanism.
