High-efficient noble-metal-free photocatalyst is vital to realize high H 2 evolution. In consideration of this, we design a [email protected] reinforced concrete structure derived from nickel foam (NF) via a simp...
High-efficient noble-metal-free photocatalyst is vital to realize high H 2 evolution. In consideration of this, we design a [email protected] reinforced concrete structure derived from nickel foam (NF) via a simple one-pot oil bath strategy. The whole preparation process is started with the growth of NiS rods on NF. Subsequently, NiS rods are encased in CdS gradually under oil both conditions. After the combination of NiS rods and CdS, the photoelectrical properties of primeval CdS are greatly optimized, e.g. , photoelectric responsiveness, impedance and light absorption capacity. Moreover, the H 2 evolution rate of [email protected] is increased significantly from 2706 to 40601 μmol g −1 h −1 under visible-light irradiation (λ > 420 nm), which is about 15 times higher than that of pure CdS, thereby confirming the excellent synergistic effect between NiS rods and CdS. Additionally, the photocatalytic performance of [email protected] was stronger than that of CdS/NiS-NPs (6726 μmol g −1 h −1 ) and CdS-NPs/NiS (1639 μmol g −1 h −1 ), highlighting the advantages of CdS (prepared using oil bath treatment) and NiS rods (originated from NF growth). Lastly, according to experiment data and DFT calculation results, a viable mechanism for [email protected] is tentatively proposed.
With the rapid development of computer and optical technique, as a powerful measuring method in hydrodynamics, flow visualization technique is able to get much flow field information in practical engineering. It also ...
With the rapid development of computer and optical technique, as a powerful measuring method in hydrodynamics, flow visualization technique is able to get much flow field information in practical engineering. It also has an important meaning to projects and environmental areas. The image processing is the key to flow visualization for gaining flow field information. In terms of the PIV principles, the algorithm of PIV based on Fast Fourier Transformation (FFT) is studied, and the image mosaic program based on genetic algorithm has been compiled. The flow field of seabuckthorn flexible dam has been calculated and analyzed by using those methods as above-mentioned, and in the meanwhile, the application of flow visualization technique to measure the outdoor flow field has been studied exploringly, which proves that it is feasible to apply this technique to measure the large-scale outdoor flow field.
This paper presents a comprehensive analysis of the water vaporization in a hot water boiler system. The Computational Fluid Dynamics (CFD) technology was adopted to simulate the transient water evaporation in the boi...
This paper presents a comprehensive analysis of the water vaporization in a hot water boiler system. The Computational Fluid Dynamics (CFD) technology was adopted to simulate the transient water evaporation in the boiler termed as DZL14-1.25/115/70-AⅡ under the assumption of extreme conditions such as the water pump failure. The results indicated that the average pressure in the pipeline increased from 0.57Mpa to 0.66Mpa (the setting pressure of the safety valve) within 1050s. The pressure increased rapidly with the time increase. The average temperature of hot water changed linearly with time, and the internal thermal deviation of the hot water pipeline in the boiler decreased with time. The internal vaporization phenomenon of the hot water boiler became significant under the extreme condition. The steam flowed upward and accumulated in the upper part of the boiler shell. At 1050s, the vapor volume fraction in the hot boiler was 1.05%, which indicated that the safety valve above the stream shell need to be opened in time after 1050s to ensure the safety of the boiler.
Decarbonizing N 2 conversion is particularly challenging, but essential for sustainable development of industry and agriculture. Herein, we achieve electrocatalytic activation/reduction of N 2 on X/Fe−N−C (X=Pd, Ir an...
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Decarbonizing N 2 conversion is particularly challenging, but essential for sustainable development of industry and agriculture. Herein, we achieve electrocatalytic activation/reduction of N 2 on X/Fe−N−C (X=Pd, Ir and Pt) dual-atom catalysts under ambient condition. We provide solid experimental evidence that local hydrogen radical (H*) generated on the X site of the X/Fe−N−C catalysts can participate in the activation/reduction of N 2 adsorbed on the Fe site. More importantly, we reveal that the reactivity of X/Fe−N−C catalysts for N 2 activation/reduction can be well adjusted by the activity of H* generated on the X site, i.e., the interaction between the X−H bond. Specifically, X/Fe−N−C catalyst with the weakest X−H bonding exhibits the highest H* activity, which is beneficial to the subsequent cleavage of X−H bond for N 2 hydrogenation. With the most active H*, the Pd/Fe dual-atom site promotes the turnover frequency of N 2 reduction by up to 10 times compared with the pristine Fe site.
Oxide-derived Cu (OD−Cu) featured with surface located sub-20 nm nanoparticles (NPs) created via surface structure reconstruction was developed for electrochemical CO 2 reduction (ECO 2 RR). With surface adsorbed hydr...
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Oxide-derived Cu (OD−Cu) featured with surface located sub-20 nm nanoparticles (NPs) created via surface structure reconstruction was developed for electrochemical CO 2 reduction (ECO 2 RR). With surface adsorbed hydroxyls (OH ad ) identified during ECO 2 RR, it is realized that OH ad , sterically confined and adsorbed at OD−Cu by surface located sub-20 nm NPs, should be determinative to the multi-carbon (C 2 ) product selectivity. In situ spectral investigations and theoretical calculations reveal that OH ad favors the adsorption of low-frequency *CO with weak C≡O bonds and strengthens the *CO binding at OD−Cu surface, promoting *CO dimerization and then selective C 2 production. However, excessive OH ad would inhibit selective C 2 production by occupying active sites and facilitating competitive H 2 evolution. In a flow cell, stable C 2 production with high selectivity of ∼60 % at −200 mA cm −2 could be achieved over OD−Cu, with adsorption of OH ad well steered in the fast flowing electrolyte.
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