Activity

  • Erichsen Greenberg posted an update 10 months, 3 weeks ago

    Highly photoactive FeVO4 photoanodes with ordered nanoblock morphology and uniform Ti-doping were prepared by drop-casting mixed Ti and V precursors onto FeOOH nanorod films and following an annealing process. The results indicate that Ti4+ is uniformly doped into the FeVO4 lattice by substituting V5+ and provides an increased number of O2- vacancies. The optimized film thickness and doping level are 620 nm and 0.3%, respectively. Compared to the undoped sample, the Ti-doped photoanode showed ~ 219% enhancement in photocurrent at 1.0 V vs Ag/AgCl under back illumination of AM 1.5, reaching a state-of-the-art value of ~ 1.47 mA cm-2, and also achieved stable and efficient overall water splitting activity with evolution rates of 28.3 and 14.1 μmol cm-2h-1 for H2 and O2, respectively. The excellent PEC performance could be attributed to the remarkably enhanced charge carrier concentration and conductivity, and the facilitated charge transfer kinetics across the semiconductor/electrolyte interface, as a result of Ti-doping.

    When a liquid droplet is confined between two non-parallel hydrophobic surfaces with dihedral angle α, its behavior is largely influenced by the asymmetric confinement. During evaporation, the droplet morphology under confinement will continuously evolve, leading to the directional transport of the droplet towards the cusp.

    During the evaporation process, droplets at different initial locations l

    from the cusp were experimentally observed to transport towards the cusp. A series of simulations using Surface Evolver were performed to obtain the three-dimensional morphologies of the confined droplets. Force and energy analyses were conducted to unveil the mechanisms dominating the evaporation-triggered actuation and transport.

    The asymmetrically confined droplet of volume V would drift towards an equilibrium location of l

    from the cusp with the lowest energy. Its directional motion results from the consecutively decreasing l

    , which is scaled as l

    V

    during evaporation. Herein, the creeping and slipping modes of transport could be characterized as the quasi-stable and unstable self-relaxation processes of droplet from the stretched regime to the equilibrium regime, respectively. Our findings on the intrinsic mechanism of droplet actuation shed light on a novel approach to manipulating the confined droplet behaviors in a passive and decisive fashion.

    The asymmetrically confined droplet of volume V would drift towards an equilibrium location of le from the cusp with the lowest energy. Its directional motion results from the consecutively decreasing le, which is scaled as le~α-1V13 during evaporation. Herein, the creeping and slipping modes of transport could be characterized as the quasi-stable and unstable self-relaxation processes of droplet from the stretched regime to the equilibrium regime, respectively. Our findings on the intrinsic mechanism of droplet actuation shed light on a novel approach to manipulating the confined droplet behaviors in a passive and decisive fashion.In this research, copper(II)-alginate (Cu(II)-A) beads containing polyethyleneterephthalate derived activated carbon (PET-AC) with porous structure were prepared by a feasible cross-linking technology. The composition and structure of the beads were thoroughly analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller adsorption, scanning electron microscopy and energy dispersive X-ray methods. The desulfurization activity of the adsorbent for dibenzothiophene (DBT) in the model oil was investigated. The influence of mass ratio of PET-AC on the features of the prepared Cu(II)-A beads was studied. According to experimental results, higher adsorption capacity was acquired from PET-AC/Cu(II)-A at 41 mass ratio due to its high porosity and available Cu(II) adsorption centers. The adsorption isotherms could be correlated by the Langmuir isotherm and the maximum adsorption capacity reached up to 62.9 mg g-1. The adsorption data showed better fitting (R2 greater than 0.99) to the pseudo-second-order rate equation. Lewis acid-base and π-π interactions might be the driving force of the DBT adsorption. The adsorbent could be also reused for 4 successive runs with negligible loss in desulfurization capability. All of these features make the PET-AC/Cu(II)-A as a potential adsorbent towards desulfurization from fuels.Hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are the two branches of artificial overall water splitting (OWS), in which the reaction efficiency usually depends on different specific catalysts. Although effective bifunctional electrocatalyst for OWS (HER and OER) are highly desired, designing and constructing such suitable materials is full of challenges to overcome several difficulties, involving slow kinetics, differences in catalytic mechanisms, large overpotential values, and low round-trip efficiencies. In this work, we reported a new bifunctional electrocatalyst Ru/RuO2-MoO2 catalyst (RRMC) via a redox solid phase reaction (RSPR) strategy to achieve the high electrocatalytic activity of OWS. DIRECT RED 80 chemical structure Briefly, due to the restricted transport behavior of atoms in solid state precursor, the designed redox reaction occurred between the adjacent part of RuO2 and MoS2, forming Ru/RuO2 hybrid NPs and MoO2 plane. Therefore, the newly formed Ru/RuO2 hybrid NPs and MoO2 plane were tightly combined and used as an electrocatalyst for OWS. Benefiting from the exposed active sites and optimized electronic structure, the RRMC sample annealed at 500 °C (RRMC-500) exhibited low overpotential for HER (18 mV) and for OER (260 mV) at 10 mA cm-2 under alkaline conditions. Especially, a low cell voltage of 1.54 V was required at 10 mA cm-2 under alkaline condition.Design of highly efficient heterojunctions for photocatalytic hydrogen evolution is of significant importance to address the energy shortage and environmental crisis. Nevertheless, the smart design of semiconductor-based heterojunctions at the atomic scale still remains a significant challenge hitherto. Herein, we report novel atomic CdS/ZnIn2S4 heterojunctions by in-situ epitaxially growing 2D ZnIn2S4 nanosheets onto the surface of 1D defective CdS nanorods. The strong electronic coupling between defective CdS and ZnIn2S4 is confirmed by transient photocurrent response measurements, •O2- and •OH radicals experiments, and PL results, leading to accelerated interfacial charge separation and transfer. Additionally, the elevated charge transfer and electronic coupling are further confirmed by theoretical calculations. Consequently, CdS/ZnIn2S4 hybrids exhibit superior photocatalytic hydrogen generation activity to pristine CdS. Our findings offer a new paradigm for designing atomic 1D/2D heterojunctions for efficient solar-driven energy conversion.