具有可調能帶結構的超細多孔氮化碳束同時實現太陽能光解水和選擇性苯甲醇氧化
作者:
小柯機器人發布時間:2020/11/5 16:26:44
黑龍江大學化學與材料科學學院的付宏剛研究團隊經過不懈努力,獲得了一種具有可調能帶結構的超細多孔氮化碳束,並用其同時實現太陽能光解水和苯甲醇的選擇性氧化。 該項研究成果發表在11月3日的《德國應用化學》上。
在這項研究中,課題組通過熱解由L-精氨酸和三聚氰胺製備的不對稱超分子前體,合成了獼猴桃樣氮化碳(ACN)束。ACN束擁有可調帶隙(2.25 eV ~ 2.75 eV)和具有超薄孔壁的中空毛細管,這些特點起到了豐富反應位點、提高可見光吸收和電荷分離的作用。在苯甲醇存在的條件下,ACN束展示出優秀的純水光解能力(95.3 μmol / h),同時在日光照射下,苯甲醇被選擇性氧化為苯甲醛(90.9%轉化率和99.7%選擇性)。
通過2D同位素標記、分離和檢測,該反應中釋放的氫氣中的質子被證實來自於水。在此基礎上,研究人員推導出水光解和苯甲醇氧化的機理,有望為在一個系統中同時利用光生電子和空穴提供更多靈感。
據了解,具有多種功能(包括有機合成和水分解)的光催化劑的理性設計充滿希望,但也非常具有挑戰性。
附:英文原文
Title: Ultrathin Porous Carbon Nitride Bundles with an Adjustable Energy Band Structure toward Simultaneous Solar Photocatalytic Water Splitting and Selective Phenylcarbinol Oxidation
Author: Honggang Fu, Baogang Wu, Liping Zhang, Baojiang Jiang, Qi Li, Chungui Tian, Ying Xie, Weizuo Li
Issue&Volume:03 November 2020
Abstract: Rational design of photocatalysts with multiple functions, including organic synthesis and water‐splitting, is promising and challenging. Herein, we synthesized actiniae‐like carbon nitride (ACN) bundles based on the pyrolysis of an asymmetric supramolecular precursor prepared from L‐arginine (L‐Arg) and melamine. ACN has adjustable band gaps (2.25 eV ~ 2.75 eV) and hollow microtubes with ultrathin pore walls, which enrich reaction sites, improve visible‐light absorption and enhance charge separation. In the presence of phenylcarbinol, ACN exhibited excellent pure water‐splitting ability (95.3 μmol/h) and in the meanwhile phenylcarbinol was selectively oxidized to benzaldehyde (conversion of 90.9%, selectivity of 99.7%) under solar irradiation. For the concurrent reactions, 2D isotope labeling, separation and detection were conducted to confirm that the proton source of released hydrogen is water. Further, we theorized the mechanism of water splitting and phenylcarbinol oxidation and hope that it provides inspiration for simultaneous utilization of photogenerated electrons and holes in one system.
DOI: 10.1002/anie.202013753
Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202013753