Qiushi Ruan,Xufeng Xi,Bingzhen Yan,Lingqiao Kong,Chaoran Jiang,Junwang Tang,ZhengMing Sun
Considering the intermittent solar energy availability, storing excess photon energy for subsequent use in dark represents a decoupled solar energy utilization strategy, resembling the dark reduction process in natural photosynthesis. Multi-electron accumulation is key to such dark photosynthesis. However, accompanied by energy loss of stored photoelectrons, dark hydrogen generation suffers from low efficiency. Here, we demonstrate the efficient release of hydrogen from methanol reforming in the dark over a TiO x /CN faradaic junction. Under irradiation, photoelectrons generated from polymeric carbon nitride (CN) were stored in an electron pool at the TiO x /CN interface with negligible energy loss via a quasi-isoenergetic process. Those stored photoelectrons slowly release active electrons for proton reduction, resulting in decoupled hydrogen generation in the dark. This storing process describes accumulation and gradual release of photoelectrons in a faradaic junction, which enables the on-demand utilization of solar energy for hydrogen generation, thereby alleviating the mismatch between solar hydrogen demand and sunlight availability.
Panpan Li,Jingde Luan,Longde Jiang,Yu Zhang,Wengang Liu,Zheng Yan,Xin Ke
High pressure wet ball milling and thermal polycondensation are used to prepare W-doped O-bridge carbon nitride (WOCN) for the rapid catalytic degradation of antibiotic rifampicin (RIF). The removal of rifampicin at a concentration of 150 mg L−1 in a dark environment reached 60% within 8 minutes and 92% after 40 minutes of visible light exposure. The rapid catalytic degradation of RIF benefits from the coupling effect of dark degradation with photocatalytic degradation, including the electron replenishment theory of dark degradation and the electrophilic attack under light irradiation. In the dark degradation reaction, the abundant delocalized electrons at the tungsten-oxygen insertion surface are captured by the dissolved oxygen to produce ˙O2−, part of which directly participates in RIF degradation, whereas the other part is oxidized to 1O2 by the holes at the carbon-rich cyano group surface and then participated in RIF degradation. The electrons consumed at the reaction site are continuously replenished through the O electron bridge, allowing RIF degradation to continue. In the photocatalytic degradation reaction, photogenerated electron holes are excited using visible light, which partly participate in the degradation of RIF through the above dark reaction pathway. Meanwhile, some photogenerated holes oxidize OH− to ˙OH and degrade RIF by electrophilic attack.
Dark aqueous-phase reactions involving the nitrosation and nitration of aromatic organic compounds play a significant role in the production of light-absorbing organic carbon in the atmosphere. This process constitutes a crucial aspect of tropospheric chemistry and has attracted growing research interest, particularly in understanding the mechanisms governing nighttime reactions between phenols and nitrogen oxides. In this study, we present new findings concerning the rapid dark reactions between phenols containing electron-donating groups and inorganic nitrite in acidic aqueous solutions with pH levels <3.5. This reaction generates a substantial amount of nitroso- and nitro-substituted phenolic compounds, known for their light-absorbing properties and toxicity. In experiments utilizing various substituted phenols, we demonstrate that their reaction rates with nitrite depend on the electron cloud density of the benzene ring, indicative of an electrophilic substitution reaction mechanism. Control experiments and theoretical calculations indicate that the nitrosonium ion (NO+) is the reactive nitrogen species responsible for undergoing electrophilic reactions with phenolate anions, leading to the formation of nitroso-substituted phenolic compounds. These compounds then undergo partial oxidation to form nitro-substituted phenols through reactions with nitrous acid (HONO) or other oxidants like oxygen. Our findings unveil a novel mechanism for swift atmospheric nitrosation and nitration reactions that occur within acidic cloud droplets or aerosol water, providing valuable insights into the rapid nocturnal formation of nitrogen-containing organic compounds with significant implications for climate dynamics and human health.
危险品化学品经营许可证（带存储）