RESUMEN
Engineering targeted and reliable charge transfer pathways in multiphase photocatalysts remains a challenge. Herein, we conceptualize the Cd@CdS-ZnO/reduced graphene oxide (rGO)/ZnS heterostructures coupled with reliable carrier migration channels and visible-light response antennas by building rGO-integrated electrochemical nanoreactors and an ion-exchange process. In this ternary catalyst, the Cd clusters and rGO perform as charge relays to boost carrier transport via the Z-scheme route and accelerate photogenerated carriers to react with surface-adsorbed substances. Meanwhile, thanks to CdS, the heterostructures have photocatalytic properties under visible light illumination and can also inhibit self-corrosion by shielding Cd clusters to avoid disrupting charge transfer channels. Therefore, the special heterostructure demonstrates fascinating photocatalytic hydrogen production activity without the intervention of cocatalysts. This work provides a feasible protocol for improving the interfaces between metals and semiconductors to achieve efficient photocatalytic hydrogen generation.
RESUMEN
Solar-driven hydrogen evolution over ZnO-ZnS heterostructures is considered as a promising strategy for sustainable-energy issues. However, the industrialization of this strategy is still constrained by suppressed carrier migration, rapid charge recombination, and the inevitable utilization of noble-metal particles. Herein, we envision a novel strategy of successfully introducing In2O3 into the ZnO-ZnS heterostructure. Benefiting from the optimized internal electric field and the charge carrier migration mode based on the direct Z-scheme, the interfacial elaborating In2O3-decorated ZnO/reduced graphene oxide (rGO)/ZnS heterostructure manifests smooth charge migration, suppressed electron-hole pair recombination, and increased surface active sites. More importantly, the in situ introduction of In2O3 optimizes the construction of the internal electric field, favoring directional light-triggered carrier migration. As a result, the light-induced electrons generated from the heterostructure can be efficiently employed for the hydrogen evolution reaction. Hence, this work would shed light on the in situ fabrication of noble-metal-free photocatalysts for solar-driven water splitting.
RESUMEN
Cadmium sulfide is a potential candidate for photocatalytic water splitting. However, CdS nanoparticles have a high recombination rate of photoinduced carriers induced by aggregation. Therefore, decreasing the recombination rate and increasing the migration rate of photogenerated carriers are essential to drive the development and application of CdS in hydrogen production. In this study, we design CdS with a three-dimensional ordered macroporous (3DOM) structure using polymethylmethacrylate as a template. It not only retains the excellent visible light response of CdS but also improves the easy recombination of photogenerated carriers in CdS nanoparticles by taking advantage of the unique ability of mass transfer, charge separation, and migration in the 3DOM structure. Meanwhile, the highly ordered periodic structure of 3DOM CdS can produce a slow photon effect of photonic crystals to obtain more photoinduced carriers. In particular, we found that a suitable stop-band position is beneficial to maximize the utilization of the slow photon effect. The photocatalytic hydrogen evolution rate of Pt-CdS is considerably improved after constructing the 3DOM structure. This study provides a new design strategy of ordered macroporous sulfide catalysts to achieve high photocatalytic activity.
RESUMEN
Many physiological functions of crustaceans show a rhythmic change to adapt to daily environmental cycles. However, daily variation in the immune and antioxidant status and its possible correlation with circulatory melatonin levels during the daily cycle have not been reported in the Chinese mitten crab, Eriocheir sinensis. In this study, the specific activities of immune and antioxidant enzymes of E. sinensis during the 24â¯h cycle and its relationship with injected doses of melatonin were evaluated. The results showed that the immune parameters in the hemolymph, such as total hemolymph count, alkaline phosphatase, lysozyme, acid phosphatase, and phenol oxidase, exhibited bimodal patterns during the 24â¯h cycle, these parameters were synchronized with the activity of antioxidant enzymes such as malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase, and catalase. However, there was only one peak in the muscle (during 1200-1600â¯h) and gills (during 0400-0800â¯h). The survival rate reached approximately 80% in 5 days when melatonin concentrations were lower than 0.05â¯g/L, significantly decreasing as melatonin concentrations increased. Four hours after melatonin injection, MDA levels in the muscle and hemolymph were significantly lower than those in the control group. Eight hours after melatonin injection, SOD levels in the hemolymph were significantly higher than those in the control group. These findings highlight the importance of considering circadian regulation of innate immunity when comparing immune responses at fixed times.
Asunto(s)
Antioxidantes/metabolismo , Braquiuros/inmunología , Ritmo Circadiano , Inmunidad Innata/fisiología , Melatonina/metabolismo , Animales , Braquiuros/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Sistema Inmunológico/efectos de los fármacos , Sistema Inmunológico/inmunología , Melatonina/administración & dosificación , Distribución AleatoriaRESUMEN
The eyestalks of crustaceans play an essential role in controlling a variety of physiological functions by converting light into hormonal signals. To obtain a more complete description of eyestalk biology in the commercially important Chinese mitten crab (Eriocheir sinensis), we conducted comparative transcriptome analysis of eyestalks during the day and at night using high-throughput sequencing on an Illumina HiSeq 4000 platform. We obtained 47,092 unigenes-including 4771 differentially expressed genes (DEGs)-from eyestalks during the day and at night. We found that 4269 DEGs were upregulated during the day and 502 DEGs were upregulated at night. We identified five DEGs that may contribute to molting, including molt-inhibiting hormone, cuticle, catalase, aquaporin, and ubiquitin-conjugating enzyme; hence, similar to other crustaceans, Eriocheir sinensis may molt at night. We further identified eight DEGs related to behavior regulation, including three glutamate dehydrogenase genes that were upregulated during the day. Thus, changes in the eyestalks may partially compensate for daily changes in illumination in the Chinese mitten crab's normal environment. Our present study is the first genome-wide transcriptome analysis of the eyestalks of Eriocheir sinensis during the day and at night. Our findings provide a valuable insight into the molecular basis of circadian cycle regulation in crustaceans.