泥碳基氮掺杂多孔炭用于光热辅助可见光光解水制氢

Peat-derived nitrogen-doped porous carbons as photothermal-assisted visible-light photocatalysts for water splitting

  • 摘要: 光催化析氢反应被认为是最有前途的制氢方法之一。炭材料是大规模、低成本光解水制氢的潜在催化材料,然而目前其光催化活性仍旧较低,还不足以满足实际应用要求。本文以廉价易得的泥炭为原料,通过与尿素共炭化制备了一种氮掺杂多孔炭,作为光热辅助可见光催化剂,利用炭材料优异的光热效应提高体系温度,进而提高光催化活性。在可见光照射下,这种泥碳基炭材料可使体系温度在15 min内从室温提高至55 °C,光催化活性提高25%左右。系统考察了结晶度与氮掺杂含量对炭材料光催化性能的影响,发现在光热效应的促进下,N含量为4.88 at%且有适宜结晶度的炭材料表现出优异的光催化性能,析氢速率达到75.6 μmol H2 g−1 h−1

     

    Abstract: Photocatalytic H2 evolution is considered one of the most important processes for H2 production. Carbon materials are potential candidates for large-scale and cost-effective photocatalytic water splitting, yet their activity needs to be further improved. We report the synthesis of nitrogen-doped porous carbons using peat moss as a precursor and urea as a nitrogen source. The properties of carbons as photothermal-assisted visible-light photocatalysts were investigated. Due to the photothermal effect, the system temperature increased quickly to 55 °C in 15 min under visible light irradiation, which subsequently helps increase the photocatalytic activity by about 25%. It has been found that the crystallinity and nitrogen content of the carbon materials can be changed by changing the carbonization temperature, and these have an impact on their photocatalytic activity. A peat-derived carbon carbonized at 800 °C, with a N content of 4.88 at.% and an appropriate crystallinity has an outstanding photocatalytic activity with a high H2 evolution rate of 75.6 μmol H2 g−1 h−1 under visible-light irradiation.

     

/

返回文章
返回