查看更多>>摘要：Rechargeable seawater batteries (SWBs) are recently considered as a new approach in next-generation energy storage. However, the presence of chloride ions inhibits the performance and durability of the air cathode electrocatalysts. This study is the first research to report the effect of the built-in electric field on corrosion prevention via Cl~- repulsion. Our DFT model successfully demonstrated the near-surface charge transfer at the interface of cobalt core and pyridinic-N graphene (Co (fcc)/N-Gr) strongly contributed to advanced catalytic activity and selectively Cl~- repulsion in seawater electrolyte. Experimentally, the structure of a few layered N-doped graphene encapsulated cobalt (Co 4 mmol-N/C) showed superior catalytic activity in both alkaline (AE (Ej=10 - E_(1/2)) = 0.774 V) and seawater (△E = 1.167 V). Furthermore, Co 4 mmol-N/C demonstrated an extremely low overpotential (0.56 V) at 0.1 mA and presented superior stability for 100 h in a rechargeable SWB.
查看更多>>摘要：Regulating the rational wettability on gas-diffusion electrodes (GDEs) plays a pivotal role to improve the efficiency of CO2RR via fine-tuning the reaction zone and boosting the formation of triple-phase interfaces. Herein, we present a wettability regulation strategy that modulates the triple-phase reaction zone in the catalyst layer of GDEs. This strategy was employed on a flow-through hollow fiber GDE coated with a Bi-embedded catalyst layer. Compared to other ex-situ methods (e.g., adding wetting agents) affecting the bulk of electrocatalysts or catalyst layer, we create distinctive hydrophilic-hydrophobic regions within the catalyst layer. Catalyst layer with hydrophilic-hydrophobic regions outperforms the fully hydrophilic one by facilitating the species transport, boosting triple-phase interface formation, and maximizing the active sites. This regulation strategy showed stable wettability during CO2RR cathodic conditions, evidenced by the direct measurement of penetration depth. The electrode with the regulated wettability exhibited over 80% catalyst utilization and 4 times higher formate partial current density (-150 mA cm~(-2) with FE_(formate)> 90%) compared to the untreated electrode, outperforming other GDEs employed for CO2RR to formate in the same concentrations of bicarbonate. The finding of this versatile microenvironment regulation strategy can be extended to GDEs used for other gas-phase reactions.
查看更多>>摘要：A facile and effective impregnation method is employed to synthesize the space-confined growth of lead-free halide perovskite Cs3Bi2Br9 in MCM-41 molecular sieve. This MCM-41 @CBB (Cs3Bi2Br9) composite shows an outstanding performance for the photocatalytic reduction of CO2 to CO at the gas-solid condition under visible-light irradiation. The CO production rate of the MCM-41 @ 50 wt% CBB is determined to be 17.24 μmol g~(-1) h~(-1), which greatly exceeds that of pure CBB (1.89 μmol g~(-1) h~(-1)). The composite is highly stable showing no apparent decrease in the catalytic activity after 8 cycles of repeated experiment. The performance of space-confined growth of CBB nanoparticles in the serial molecular sieve exhibits 2.97-13.4 fold higher than that of pure CBB, respectively, which is superb than CPB (CsPbBr3) and MCM-41 @CPB prepared in the same condition. The results are comparable with those reported for many lead halide perovskites, and are in the top among the lead-free perovskites, especially bismuth halide perovskites.
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