查看更多>>摘要：Fabrication of broad-spectrum response photocatalysts in a controllable manner that can efficiently utilize solar light as much as possible remains a top priority target yet a challenging task. In this work, a facile approach of synchronous bottom-up growth was employed to construct UCNP/NMIL(Ti) nanohybrids via NH2-BDC (NH2- MIL-125-ligand) linkage between upconversion NaYbF4:Tm3+ nanoparticles (~13-nm) and NH2-MIL-125. The ligand sharing integration strategy generated abundant oxygen vacancies and coordinatively-unsaturated-metal sites, efficiently enhanced light absorption, energy-transfer upconversion (UC-PL), photo-induced e -/h+ generation, and their separation (CV, EIS, Photocurrent-density). Consequently, UCNP/NMIL(Ti) exhibited excellent acetaldehyde photodegradation activity, with 12.5-77.0-folds higher rate constants (k(a)) than those of state-ofthe-art photocatalysts under visible light and high humidity. Furthermore, the photocatalytic activity of UCNP/NMIL(Ti) only declined from 96.0% to 92.5% after five cycling-runs, demonstrating its remarkable photo catalytic stability. Considering these attributes, the current strategy provides an avenue to synthesize efficient UCNPs/MOF composites for widespread usage in a variety of commercial applications.
查看更多>>摘要：Strong metal support interaction between Ni and gamma-Al2O3, resulted from the excessive hydroxyl groups on the Al2O3 support, has restricted Ni utilization in the traditional Ni/Al2O3 catalyst, which hampered its commercial application. Meanwhile, the concept of surface defects in activating single-carbon chemicals of CH4 and CO2 has attracted much attention in heterogeneous catalysis. Thus, designing better Ni/Al2O3 system in generating surface defects without losing active Ni into Al2O3 support remains challenging. Herein, the development of tailored defect sites on Al2O3 through hydroxyl-exposed strategy shows dual role of stabilizing the active Ni sites and holding responsible for catalyzing CH4 dry reforming (DRM) reaction via a more efficient route, which emphasizes the superior behavior of the traditional Ni/Al2O3 catalyst. It is considered that it can be appropriately used for reactions using not only excellent DRM catalysts but also other Ni catalysts.
查看更多>>摘要：Electrocatalytic nitrate reduction reaction (NitRR) has gained attention because of its potential to mitigate environmental nitrogen pollution and recycle artificial nutrients. NitRR produces ammonia through complicated pathways that involve multistep electron transfer, while the formation of byproducts, e.g. toxic nitrite (NO2-), leads to lower energy efficiency and recontamination. In this work, we report the incorporation of CuOx active species into a TiO2-nanotube reactor (TiO2 NTs/CuOx) for the highly selective NitRR. In particular, the NO2- intermediate is diminished due to the hindered diffusion within the nanoconfined space. Thus, the CuOx modified nanoreactor performs a maximum faradaic efficiency of 92.23% and a yield rate of 1241.81 mu g h(-1) cm(-2) for nitrate-to-ammonia conversion. Theoretical insights further support a fundamental understanding of a cross scale interaction over the surface and interface. The findings suggest a promising approach for enhancing reaction activity and selectivity enabled by rationally designed active sites coupled with geometrically regulated structures.
查看更多>>摘要：Ground-level ozone causes great harm both to ecosystems and human health and should be strictly controlled. Manganese oxide (MnOx) is severely limited by catalyst deactivation due to environmental variations such as humidity and temperature. Herein, amorphous MnOx, prepared via a simple and mild redox reaction showed complete elimination of 40 ppm ozone at a high weight hourly space velocity of 600,000 mL.g(-1) h(-1), under the mild environmental condition with the relative humidity of 50 % and 25 ?C. It also kept predominant activity and remarkable stability even at harsh environmental conditions of low temperature (0 ?C) or high humidity (90 %). The superior ozone decomposition performance of MnOx resulted from the abundant grain boundaries and manganese redox pairs, which promoted oxygen vacancies generation and electron transfer. The findings may shed new light on the design of highly efficient and stable MnO(x )catalysts and are expected to drive great advances for large-scale practical applications.
查看更多>>摘要：Poisoning species, such as methanol and air pollutants, degrade the electrocatalytic activity for oxygen reduction reaction (ORR). Here, via taking advantage of the varied electronic property of nano-silicon, a versatile strategy is reported for enhancing the catalytic activity and anti-poisoning ability toward ORR by decorating noble metal catalysts with the size-controlled silicon nanoclusters (DS). Consequently, DS-Pd exhibits the enhanced ORR performance with a large halfwave potential of 0.892 V and an onset potential of 1.010 V. More importantly, it also shows enhanced anti-poisoning performance in methanol, NaNO2 and NaHSO3 electrolytes, compared to those of commercial Pt/C and Pd/C catalysts. Mechanism studies reveal that the synergistic effect between Pd and more oxygen-philic and less poison-philic Si nanoclusters largely abbreviate the absorption of poisoning species on the active sites. This strategy also improves the methanol-tolerant performance of Pt based catalysts, providing a versatile strategy for the fabrication of methanol-tolerant ORR catalysts.
查看更多>>摘要：This study develops an advanced single-atomic iron-loaded graphitic carbon nitride (Fe-1/CN) with unparalleled efficiency for converting peroxymonosulfate (PMS) to oxidants for water treatment. We found that acid-etching of Fe-1/CN leads to the reconstruction of conventional Fe-1-N-4 to Fe-1-C2N1 active sites. The acid-induced Fe-1-C2N1 sites are more favorable for PMS binding and have a lower energy barrier for O-1(2) production. The precise tuning of the coordination environment bestows the acid-etched Fe-1/CN with 29 times higher rate constants of bisphenol A degradation than its pristine counterparts. Further, the particulate catalysts were assembled into a self-supported catalytic membrane, which demonstrates excellent long-term durability throughout 170 h flow-through tests in both synthetic and real wastewater. This work provides pivotal insights into improving PMS activation activity by regulating the coordination environment around single atomic Fe sites. The engineering innovation laid the groundwork for new point-of-use water treatment devices.
查看更多>>摘要：Ti3+ self-doped Fe2O3/TiO2 ultra-thin nanoflakes have been fabricated on Ti-substrate by a facile hydrothermal route. The high solar light harvest by Ti3+ and oxygen vacancies makes Ti3+ self-doped Fe2O3/TiO2 ultra-thin nanoflakes an attractive candidate for photo-activation of peroxymonosulfate (HSO5-) for the degradation of naphthalene (NAP). The Fe2O3/TiO2 ultra-thin nanoflakes synthesized with 0.053 M of FeCl3 (TF3) exhibited high concentrations of Ti(3+ )and oxygen vacancies. TF3/ HSO5- /solar light system showed substantial increases in the degradation of NAP with kapp value of 0.1384 min(-1) compared to 0.057 min(-1) when no HSO5- was added to the system. The proposed system also showed appreciable degradation of NAP in real water samples. Based on scavenger studies, SO4 center dot-, center dot OH, h+ and O-2(center dot-) are generated in the reaction system. Importantly, the toxicity results indicated that the proposed system (TF3/HSO5- /solar light) is an efficient treatment process for detoxifying water contaminated with NAP.
查看更多>>摘要：A constructed MoS2/Bi2S3/BiVO4 ternary photocatalyst(MBB) mainly with a S-scheme heterostructure was loaded on a 3D lignosulfonate modified poly(vinyl formal) sponge to obtain a novel composite sponge(PLS-MBB) with an enhanced performance in synergistic adsorption and photo-Fenton degradation of various fluoroquinolones(FQs) in water. The synergistic adsorption and photocatalysis of PLS-MBB notably improved the applicable pH from 2.0 to 9.0 and reduced the dosage of Fe2+ to 0.014 mmol/L in Fenton reaction, which could achieve the degradation efficiency of 92.8 % for FQs within 60.0 min at pH 6.0. The photo-generated electrons by MBB and the redox transformation of Mo(IV)/Mo(VI) and Bi(III)/Bi(V) accelerated the conversion of Fe3+ to Fe2+; besides, the efficient adsorption of FQs on the sponge carrier promoted the surface degradation in solution, thereby causing an enhanced photo-Fenton reaction. This work provided a novel strategy to improve photo-Fenton reaction and accordingly fabricated a talented material for effective removal of organic contaminants in water.
查看更多>>摘要：Various MnOx phases and crystals were investigated in peroxymonosulfate (PMS) activation for oxidation of aqueous phenolic pollutants. MnOx with controlled crystal structure (alpha, beta, gamma, and amorphous-MnO2) and redox states (Mn2O3, and MnO) can induce different oxidative pathways toward organic polymerization against degradation in acidic conditions. Surface Mn-(s())II and Mn-(s)(III) of MnOx tend to bond with PMS to generate confined Mn-(s)((II, III))-(HO)OSO3- complexes to initiate a nonradical electron-transfer pathway (ETP). Meanwhile, high valence Mn/vs) in MnOx will directly attack micropollutants and spontaneously be reduced to low-valence states (Mn-(s)(II) and Mn-(s())III to initiate ETP. Mn2O3 can activate PMS to generate other radical species for mineralization. ETP will selectively initiate one-electron abstraction of phenol molecules into monomer phenoxy radicals and polyphenols on catalyst surface. Thus, manganese crystal structures will govern the surface redox species to induce multiple oxidation pathways toward different polymer products for water decontamination and carbon recycle.
查看更多>>摘要：Although great interest is focused on development of semiconductor photoanodes for efficient photo electrochemical (PEC) water splitting, the pressing bottleneck to address the intrinsic charge transport for enhancement of PEC performance still remains to be resolved. Herein, hole transport layer (Fh-MXene) constructed by doping of MXene (Ti3C2) in Ferrihydrite (Fh) is loaded on BiVO4 photoanode. This novel BiVO4@Fh-MXene photoanode achieves high current density of 4.55 mA cm(-2) at 1.23 V versus reversible hydrogen electrode (vs. RHE), exhibiting excellent photostability. From electrochemical analysis and density functional theory calculations, high PEC performance is ascribed to incorporation of Fh-MXene as hole transport layer, enhancing conductivity and water oxidation reaction. Notably, MXene can improve band alignment of BiVO4/Fh-MXene interface by tuning work function, which strengthens the built-in electric field for more efficient hole extraction. This work provides a simple method to design photoanodes with efficient charge transport layers for feasible PEC water splitting application.
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Elsevier