RESUMO
Ir-based materials are still the benchmark catalysts for various reactions in acidic environment, but the high loading and low atom utilization limit their large-scale deployment. Herein, we report an effective strategy for implanting fully dispersed iridium-oxide atomic clusters onto hematite for boosting photoelectrochemical water oxidation in acidic solution. The resulting photoanode achieves a record-high photocurrent of 1.35 mA cm-2 at 1.23 V, corresponding to a mass activity of 172.70 A g-1 (3 times higher than electrodeposited control sample) and demonstrating the merits from the high atomic utilization of Ir. The systematically experimental and theoretical results reveal that the performance improvement correlates with the modulated electronic structure including the adjusted Fermi level and d-band center, which significantly enhances charge separation efficiency and promotes the conversion from intermediate *O into *OOH.
RESUMO
Cellulose nanocrystals (CNCs) is an exciting class of sustainable and carbohydrate material, which has great potential applications in molecular adsorption. However, the complex preparation process and limited adsorption capacity of CNCs hinder its commercial application. In this study, we design a novel functional cellulose nanocrystals-based adsorbent by an ingenious mixing of lignin-containing cellulose nanocrystals (LCNCs), sodium alginate (SA), and calcium chloride solution. Benefiting from the sulfonate groups of lignin, carboxyl groups of SA, the maximum adsorptive capability of LCNCs/SA beads for methylene blue was found to be 1181â¯mgâ¯g-1, which was significantly higher than previously reported biomass-based adsorbents. More importantly, LCNCs/SA beads can be reused several times. This strategy can not only improve the adsorption performance of CNCs-based materials, but also simplify the production technology of CNCs, which greatly promote the commercial application of CNCs materials.
Assuntos
Alginatos/química , Celulose/química , Corantes/química , Lignina/química , Nanopartículas/química , Adsorção , Biomassa , Cloreto de Cálcio/química , Cátions , Hidrogéis/química , Concentração de Íons de Hidrogênio , Cinética , Azul de Metileno/química , Compostos Orgânicos/química , Reprodutibilidade dos Testes , TermodinâmicaRESUMO
The influence of flue gas composition on the specific resistance of coal-fired fly ash is studied in this paper. We conclude that the negative electrons of NO2 and SO2 gases are strong. The probabilities of electron desorption on SO2 and NO2 negative ions are lower than that in air atmosphere at high temperature. Therefore, the introduction of SO2 causes NO2 to reduce the specific resistance value of coal-fired fly ash. When the pores on the surface of fly ash particles are filled with SO2, no change will occur in NO2, average pore size, pore volume, and specific surface area of fly ash particles, thereby resulting in fly ash that remains unchanged from the resistance value. When humidity increases, the surface conduction effect is greatly enhanced, and the specific resistance value is lowered considerably. Therefore, the specific resistance of dust can be reduced by humidification.