Mesoporous metals with large surface area,high pore volume,and uniform pore structure hold excellent advantages for various applications.However,the state-of-the-art synthesis methods are still limited to wet chemistry,which requires excessive solvents and a time-consuming drying process.Here,we report a facile and general mechanochemical coordination self-assembly strategy to prepare mesoporous metals(e.g.,Rh,Ru,Ir,Pt,Pd,Ag,Co,and Ni)with remarkable porous properties by using metal chlorides and cationic polymer interplay.Compared with the wet chemistry process,this method proceeds without solvents and does not need complicated experimental conditions and long synthetic periods,which not only greatly reduces the consumption of cost and energy and environmental pollution,but also improves the synthesis efficiency and yield of target products.We believe the developed approach will provide a general pathway for the scalable preparation of advanced porous materials.
The preparation of immobilized enzyme with excellent performance is one of the difficulties that restrict the application of enzyme catalysis technology.Here,Candida rugosa lipase(CRL)was firstly adsorbed on the surface of magnetic zeolitic imidazolate framework-8(ZIF-8)nanospheres,which was further encapsulated with a mesoporous SiO_(2)nano-membrane formed by tetraethyl orthosilicate(TEOS)polycondensation.Consequently,lipase could be firmly immobilized on carrier surface by physical binding rather than chemical binding,which did not damage the active conformation of enzyme.There were mesopores on the silica nano-membrane,which could improve the accessibility of enzyme and its apparent catalytic activity.Moreover,silica membrane encapsulation could also improve the stability of enzyme,suggesting an effective enzyme immobilization strategy.It showed that TEOS amount and the encapsulation time had significant effects on the thickness of silica membrane and the enzyme activity.The analysis in enzyme activity and protein secondary structure showed that lipase encapsulated in silica membrane retained the active conformation to the greatest extent.Compared with the adsorbed lipase,the encapsulated lipase increased its thermostability by 3 times and resistance to chemical denaturants by 7 times.The relative enzyme activity remained around 80%after 8 repetitions,while the adsorbed lipase only remained at7.3%.
The integration of dual-mesoporous structures,the construction of heterojunctions,and the incorporation of highly concentrated oxygen vacancies are pivotal for advancing metal oxide-based gas sensors.Nonetheless,achieving an optimal design that simultaneously combines mesoporous structures,precise heterojunction modulation,and controlled oxygen vacancies through a one-step process remains challenging.This study proposes an innovative method for fabricating zinc stannate semiconductors featuring dual-mesoporous structures and tunable oxygen vacancies via a direct solution precursor plasma spray technique.As a proof of concept,the resulting zinc stannate-based coatings are applied to detect 2-undecanone,a key biomarker for rice aging.Remarkably,the zinc oxide/zinc stannate heterojunctions with a well-defined secondary pore structure exhibit exceptional gas-sensing performance for 2-undecanone at room temperature.Furthermore,practical experiments indicate that the developed sensor effectively identifies adulteration in various rice varieties.These results underscore the potential of this method for designing metal oxides with tailored properties for high-performance gas sensors.The enhanced adsorption capacity and dual-mesoporous features of this semiconductor make it a promising candidate for sensing applications in agricultural food safety inspections.
