A novel organic semiconductor photocatalyst mimicking natural light-harvesting antenna complexes in photosynthetic organisms, a disulfide (-S-S-) bridged C 3 N 3 S 3 polymer, was designed and developed to generate hydrogen from water under visible light irradiation. The artificial conjugated polymer shows high H 2 -producing activity from the half-reaction of water splitting without the aid of a sacrificial electron donor. The H 2 -producing efficiency and photo-stability of the catalyst could be improved greatly using Ru and single-wall carbon nanotubes as cocatalysts or by adding a sacrificial donor. The results represent a potential and prospective application of the C 3 N 3 S 3 polymer in solar energy conversion and offer significant guidance to develop more stable and efficient photocatalytic systems based on organic semiconductors.
Background
Environmental pollutants, which coexist with allergens, have been associated with the exacerbation of asthma. However, the underlying molecular mechanisms remain elusive. We sought to determine whether benzo(a)pyrene (BaP) co‐exposure with dermatophagoides group 1 allergen (Der f 1) can potentiate Der f 1‐induced asthma and its underlying mechanisms.
Methods
The effect of BaP was investigated in Der f 1‐induced mouse model of asthma, including airway hyper‐responsiveness, allergic inflammation, and epithelial‐derived cytokines. The impact of BaP on Der f 1‐induced airway epithelial cell oxidative stress (ROS) and cytokine release was further analyzed. The role of aryl hydrocarbon receptor (AhR) signaling in BaP‐promoted Der f 1‐induced ROS, cytokine production, and allergic inflammation was also investigated.
Results
Compared with Der f 1, BaP co‐exposure with Der f 1 led to airway hyper‐responsiveness and increased lung inflammation in mouse model of asthma. Increased expression of TSLP, IL‐33, and IL‐25 was also found in the airways of these mice. Moreover, BaP co‐exposure with Der f 1 activated AhR signaling with increased expression of AhR and CYP1A1 and promoted airway epithelial ROS generation and TSLP and IL‐33, but not IL‐25, expression. Interestingly, AhR antagonist CH223191 or cells with AhR knockdown abrogated the increased expression of ROS, TSLP, and IL‐33. Furthermore, ROS inhibitor N‐acetyl‐L‐cysteine (NAC) also suppressed BaP co‐exposure‐induced expression of epithelial TSLP, IL‐33, and IL‐25. Finally, AhR antagonist CH223191 and NAC inhibited BaP co‐exposure with Der f 1‐induced lung inflammation.
Conclusions
Our findings suggest that BaP facilitates Der f 1‐induced epithelial cytokine release through the AhR‐ROS axis.
Herein, we reported a octahedral Cd3(C3N3S3)2 coordination polymer as a new noble metal-free photocatalyst for robust photocatalytic H2O2 production from methanol/water solution. The coordination polymer can give an unprecedented H2O2 yield of ca. 110.0 mmol • L−1 • g−1 at pH = 2.8 under visible light illumination. The characterization results clearly revealed that the photocatalytic H2O2 production proceeds by a pathway of two-electron reduction of O2 on the catalyst surface. This work showed the potential perspective of Mx(C3N3S3)y (M = transitional metals) coordination polymers as a series of new materials for solar energy storage and conversion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.