查看更多>>摘要：Strontium iridate perovskites are alternative electrocatalysts for oxygen evolution reaction (OER) in acidic media. Nevertheless, their practical feasibility is still hindered by structural stability due to the inevitable Sr leaching during long-term electrocatalysis. Herein, we propose a 0D/2D heterostructure involving CeO2 quantum dots decorated SrIrO3 nanosheets to achieve durable and active OER in harsh acidic environment. Theoretical calculations unveil that CeO2 coupling with electronic rearrangement not only lowers the energy barrier of OER but also mitigates Sr leaching. Benefiting from the activation and stabilization dual-effect of CeO2 coupling, the 4CeO(2)@SrIrO3 heterostructure exhibits an ultralow overpotential of 238 mV at 10 mA cm(-2) and a good durability for 50 h, surpassing most perovskite-related electrocatalysts in acidic media. For acidic water splitting, the water electrolyzer assembled with 4CeO(2)@SrIrO3||Pt-C coupled electrode demonstrates high activity and longlasting life. This protocol highlights an elegant approach of engineering heterostructure for robust and efficient electrocatalysis.
Kim, SangwooJung, Ji-WonSong, DongHoonCho, Su-Ho...
10页
查看更多>>摘要：The lack of bifunctional features of perovskite oxide toward the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) significantly limits its use as a cathode catalyst for rechargeable Zn-air batteries (ZABs). Thus far, numerous techniques to disperse additional catalysts on a perovskite host have been suggested to overcome this problem; however, cost-effectiveness and catalyst lifespan remain unsatisfactory. Herein, we present cobalt-based-nanoparticle-decorated Sr0.95Nb0.1Co0.7Fe0.2O3-delta (S0.95NCF) by a simple ex-solution method and use it as a novel air-electrode catalyst. We successfully implemented the socketed nanoparticles with various compositions at different reduction temperatures, achieving notably enhanced activity towards OER and ORR. More importantly, the newly designed catalyst exhibits record-high charge/discharge durability over 500 h (or 1500 consequent cycles) when used as the ZABs cathode. Our findings provide essential guidelines for designing heterostructured electrocatalysts for future energy devices, in which multifunctionality is desirable.
查看更多>>摘要：The increasingly massive consumption of plastics is becoming a global pollution disaster, with serious environmental and economic problems. Here we report an efficient and sustainable strategy for the visible-light driven upcycling of various plastic wastes into high-value-added formic acid. We firstly design and fabricate a self-assembly Z-scheme heterostructure of V-substituted phosphomolybdic acid clusters/g-C3N4 nanosheets (VPOM/CNNS). The Z-scheme charge transfer process is unambiguously elucidated by transient absorption spectra and electron spin resonance studies, which endow VPOM/CNNS heterostructure with efficient charge separation and strong redox potentials. Consequently, VPOM/CNNS heterostructure displays a superior photo catalytic performance toward upcycling of various plastics. The optimal VPOM/CNNS composite exhibits a remarkable formic acid production rate of 24.66 mu mol h(-1) g-1 for upcycling of polyethylene, which is 262-fold higher than that of pristine CNNS. This work highlights the potential of Z-scheme heterojunction as an unusual tool for the photo-driven upcycling of plastic waste.
查看更多>>摘要：Herein, we report a hydrogen peroxide-free resin photo-Fenton system with separation-free, low-cost, and strong mineralization ability of efficiently degrading organic pollutants (phenols, endocrine disruptors, antibiotics, and dyes). Based on the synergistic effect of hydroxyl radicals and holes, the corresponding degradation rate for Bisphenol A (BPA) was 11 times and 14.6 times higher than that of P-g-C3N4 and CdS/rGO photo-self-Fenton, respectively. The excellent performance is mainly attributed to a nearly 100% reduction of iron ions by electrons and promoted hydrogen peroxide utilization of 82.1%. Meanwhile, the introduction of strong oxidizing holes (2.15 eV) prevented the generation of macromolecular polymer intermediates, leading to a directly aromatic ring-opening and high mineralization efficiency (67%). This work exhibits a promising role of resin in visible-light photo-self-Fenton systems, offering a new route for eco-friendly and efficient wastewater treatment.
查看更多>>摘要：Maintaining stable catalytic performance for chlorinated volatile organic compounds (CVOCs) oxidation in Pbcontaining scenarios is an intractable challenge for the industrial application of Ru-based catalysts. Herein, we systematically investigated the effect of Pb poisoning on the activity over various Ru-based catalysts during the CVOCs oxidation and explored the possible Pb resistance mechanism. The source of high Pb resistance was clarified from two aspects: (1) oxygen vacancies on supports (CeO(2 )or TiO2) captured Pb and firmly locked it in lattice, namely strong capture effect; and (2) the formation of stable Ru-O-M (M = Ce and/or W) bonds weakened the affinity between active Ru sites and Pb, ensuring the preferential deposition of Pb at oxygen vacancies. With the synergistic effect of above factors, the intrinsic activity (mainly strong acidity) of Ru sites in Ru/CeO2 and RuW/TiO(2 )catalysts was retained, which ensured the efficient dissociation of C-Cl bond and oxidation of CB.
查看更多>>摘要：Despite the significant role of single atoms during the hydrogen evolution reaction (HER), the underlying nature of the synergetic effect between substrates and single atom is still unclear. Herein, through anchoring Pt single atoms on cobalt sulfide support (Pt@CoS), the roles of Pt single atoms and the substrate for alkaline HER catalysis are unfolded. Electrochemical studies demonstrate the remarkable catalytic performance of Pt @CoS catalysts with a 45-fold increase in mass current density compared to the benchmark Pt/C at 100 mV. The DFT calculation unravels that the anchored Pt SAs on CoS enable more unhybridized d(z)(2) orbitals of surrounding cobalt sites through the interfacial synergetic effect, which benefits the water dissociation kinetics. Likewise, the Pt sites can also act as active sites to facilitate the subsequent H-2 formation, thus synergistically promoting the alkaline HER catalysis. This work highlights the importance of the synergies effect between single atoms and substrate for rational catalyst design.
查看更多>>摘要：Cobalt and oxides are the most recognized catalysts for peroxymonosulfate (PMS)-based advanced oxidation processes. However, the valence states - catalysis relations remain ambiguous. Herein, Co0/CoO/Co3O4 @K, N, O-doped carbons (Co-K-N-O-C) were synthesized via low-temperature pyrolysis. The cobalt species resulted in defective and doped carbons, and KOH facilitated the formation of low-valent Co species and carbon porosity. The synergy between Co and K facilitated peroxymonosulfate (PMS) activation and ciprofloxacin (CIP) mineralization due to enhanced electron transfer. Kinetics analysis was coupled with quenching experiments, electron paramagnetic resonance (EPR) detection and chemical probe identification to elucidate the contributions of each reactive oxygen species. As a result, hydroxyl radical (HO center dot) dominated the degradation (-64.8 +/- 1.2%), followed by sulfate radicals (SO4 center dot , -34.2 +/- 1.1%) and singlet oxygen (1O2, <2.0%). The low-valent Co species, especially Co0, greatly promoted radical generation. This study dedicates to in-depth elucidation of PMS activation mechanisms over metal/oxides@carbon composites for purifying recalcitrant contaminants in wastewater.
查看更多>>摘要：This study investigates the binary role of Ti3+ self-doped TiO2 nanotubes (bl-TNA) as an anode as well as a cathode in the photoelectrochemical (PEC) oxidative treatment of organic contaminants. Compared to the Ti cathode-based asymmetric system, the symmetric PEC system with Janus bl-TNA photoelectrodes demonstrated higher interfacial charge transfer, photoresponsive activity, and kinetic constant for bisphenol-A (BPA) degradation. The bl-TNA photocathode enhanced the formation of radicals by providing additional reaction sites for photocatalytic reactions and cathodic peroxydisulfate (PDS) activation. Additionally, the rate constant ratio for BPA degradation between the anode and cathode in the symmetric system changed from 7.5:1-1.3:1 under PEC and PEC/PDS conditions, indicating that PDS addition enhanced the photoactivity of the electrodes, with a higher rate at the cathode. Finally, only 2.4% performance decline was observed after 64 h with the periodic polarity reversal operation, demonstrating the long-term stability of the proposed PEC system.
查看更多>>摘要：Solar-driven hydrogen evolution from urea-rich wastewater is a highly promising energy-environment bi-functional synthetical solution, while the intrinsic contradict between spectral energy quantity and quality of sunlight limits the existing wavelength-dependent technologies. Herein, we report the first demonstration of concentrated photo-thermo-catalysis (CPTC) technology that regulates the spectral energy quantity and quality and creates the synergy between photon and thermal effects to achieve full-spectrum solar harmonic conversion of aqueous urea and urine into hydrogen. The 50% enhanced CPTC performance compared with sole photo-/thermo-catalysis is achieved due to: (1) Catalyst structure optimization. Single Cu atom and 2D Cu raft are acquired on defect-rich TiO2 support by photo-thermo-organized metal-support interaction; (2) Reaction pathway expansion. The breakthrough against thermodynamic barrier of urea to hydrogen is realized by the novel cascade reactions of thermally-triggered urea hydrolysis and thermally-assisted ammonia photo-decomposition. The technological viability is convincingly presented through outdoor test with artificial urine under real sunlight.
查看更多>>摘要：h-BN-based electrocatalysts with low-cost and high efficiency have a great potential for electrochemical nitrogen reduction reaction (NRR). The carbon-doped boron nitride (C-BN) nanosheets are proposed as the excellent metal-free electrocatalysts for converting nitrogen to ammonia (NH3). In 0.1 M Na2SO4 solution, it obtains NH3 yield of 44.59 +/- 1.79 mu g h-1 mgcat -1 at - 0.9 V vs reversible hydrogen electrode (RHE), with a high faradaic efficiency (FE) of 13.27 +/- 0.42 % at - 0.7 V vs RHE, and an outstanding electrochemical durability. Density functional theory (DFT) calculations reveal that carbon-doping dramatically reduces the band gap to 1.40 eV and induces charge accumulation on carbon atom to facilitate N2 adsorption. The synergistic interaction of C and B atoms at the double-active-site of C-BN significantly decreases the energy barrier (from *NH-NH to *NH-NH2) for the potential-determining step. The results confirm that C-BN has the potential as an efficient metal-free NRR electrocatalyst in neutral media.
NSTL
Elsevier