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Si, as a narrow bandgap semiconductor with a broadband absorption for sunlight, is considered to be a very competitive photoelectrode material for solar-driven photoelectrochemical (PEC) water splitting. However, there are major barriers in construction of efficient and stable Si-based PEC cell, including low photovoltage, sluggish reaction kinetics, and poor stability in electrolytes. This review focuses on the strategies to solve these issues and summarizes recent progress. The working principles of PEC water splitting are first introduced. Then the strategies for improving Si-based photoelectrode performances are discussed, including (1) the regulation of Si surface morphology for enhancing light harvesting, (2) band structure engineering strategies to reduce recombination of photogenerated carriers, and (3) modification of protection layers for long stability and loading cocatalysts on Si-based photoelectrodes for accelerating water splitting. Lastly, we have presented some issues of Si-based photoelectrode materials, which should be addressed in future research.

Plant pathogens constantly develop resistance to antimicrobial agents, and this poses great challenges to plant protection. Therefore, there is a pressing need to search for new antimicrobials. The combined use of antimicrobial agents with different antifungal mechanisms has been recognized as a promising approach to manage plant diseases. Graphene oxide (GO) is a newly emerging and highly promising antimicrobial agent against various plant pathogens in agricultural science. In this study, the inhibitory activity of GO combined with fungicides (Mancozeb, Cyproconazol and Difenoconazole) against Fusarium graminearum was investigated in vivo and in vitro. The results revealed that the combination of GO and fungicides has significant synergistic inhibitory effects on the mycelial growth, mycelial biomass and spore germination of F. graminearum relative to single fungicides. The magnitude of synergy was found to depend on the ratio of GO and fungicide in the composite. In field tests, GO–fungicides could significantly reduce the disease incidence and disease severity, exhibiting a significantly improved control efficacy on F. graminearum. The strong synergistic activity of GO with existing fungicides demonstrates the great application potential of GO in pest management.

DFT investigations were employed to explore the complete reaction mechanism of the nickel‐catalyzed [3+2+2] cocyclization of ethyl cyclopropylideneacetate and alkynes. The lowest‐energy pathway involves the formation of a π complex between the methylenecyclopropane moiety and the nickel atom and occurs through a sequence of ring‐opening and ring‐closing reactions with C–C bond formation as the rate‐determining step. The crucial conversion of nickelacycloheptadiene to an eight‐membered nickelacycle was suggested to happen in a stepwise mechanism instead of the previously proposed cyclopropenyl–butenyl rearrangement.

Nanopesticides with controlled release can achieve more effective utilization of pesticides.

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