Preparation Of Dendritic Fibrous Silicon-TiHybrid Nanospheres And Study On Their Catalytic Luminescence Properties

Volatile organic compounds(VOCs)are diverse and ubiquitous.VOCs in living and industrial environments are seriously endangering the natural environment and human health.The realization of high-sensitivity detection of these VOCs is a hot topic in the field of environmental analysis in recent years.One.Ether is a kind of harmful volatile organic compound that is flammable and explosive and threatens human health and environmental safety.Therefore,it is necessary to detect ether in medicine,laboratory or industry.As an important detection method for chemiluminescence analysis,the catalytic luminescence method has the characteristics of high sensitivity,simple operation,and real-time monitoring.The catalytic material involved is the core component of the catalytic luminescence sensor.Nanomaterials,as an important class of catalytic materials,have large surface area,rich catalytic active sites,and specific characteristics of various structures.In this paper,the structure of nanomaterials is optimized,and a diethyl ether-based luminescent gas sensor based on nanomaterials is constructed.A new method for detecting ether is established.The specific content includes:1.Dendritic fibrous nano-silica(DFNS),also well-known as DFNS,possesses three-dimensional center-radialnanochannels and hierarchical nanopores.Compared with conventional mesoporous materials like SBA-15,these special structural characteristics endow DFNS with more accessible internal space,higher specific surface area,larger pore volume,etc.Even though great progress has been achieved,the as-prepared DFNS nanospheres exhibit extremely non-uniform diameters and their sizes differ enormously in almost all available traditional synthesis approaches.Herein,a facile and low-cost one-pot rotating hydrothermal approach is adopted to improve the size uniformity of dendritic fibrous nano-silica.Stirring rates of 30,60,90,120,and 150(the maximum)revolutions per minute(rpm)can influence DFNS uniformity to certain extents.Among them,60 rpm can be considered to be an ideal stirring rate for relatively uniform DFNS because of the best sufficient contact of reaction phases.A plausible synthesis mechanism can be explained in terms of continuously variable stress conditions of the reaction mother liquor(i.e.,the bicontinuous microemulsion)during the fabrication process.To be specific,except for gravity(G),this technique brings about the centrifugal force(F)stemming from the stirring rate,and the buoyancy(f)originated from vigorous reversal of organic phase in the reaction solution.These forces synergistically mix organic phase and water phase,which generates new bicontinuous microemulsion droplets(BMDs)to supplement the consumed ones.All in all,this approach as well as the synthesis equipment is simple,inexpensive,and reproducible for large-scale DFNS preparation with improved size uniformity.2.A series of DFNST nanospheres have been prepared by a two-step post-grafting method.The prepared DFNST was evenly coated on the surface of a ceramic heating rod to form a catalytic light-emitting film.A novel catalytic light-emitting ether sensor was designed.The structure and physicochemical properties of DFNST were characterized by Scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray diffractometer(XRD),inductively coupled plasma emission spectroscopy(ICP-OES),Fourier infrared spectroscopy(FT-IR)and N2 adsorption-desorption isotherm to reveal its morphology,structure,crystal form,chemical composition,pore volume,and specific surface area and discussed the catalytic luminescence mechanism of ether on the surface of DFNST catalyst.Under optimized conditions,a wavelength of 440 nm,a temperature of380 ?,and a carrier gas flow rate of 270 m L/min,the catalytic luminous intensity of the ether sensor has a good linear relationship with the ether concentration in the range of 10 to 45 m M(R2=0.99328),and the detection limit is 4 m M(S/N=3),and the relative standard deviation RSD was 2.4%(n=7).3.Selectively controllable catalytic light emitting(CTL)sensors for volatileorganic compounds(VOCs)are of great significance for chemical safety,environmental monitoring,human health,etc.Due to the high sensitivity of CTL-based sensors to interfering substances,most CTL-based sensors have relatively low response speed and low selectivity.In this study,we have optimized the dendritic fiber-shaped silicon-titanium hybrid nanospheres(DFNST)that have been synthesized and used them as a new sensing material.Corresponding DFNST-based CTL sensor for highly selective detection of ether.The as-prepared DFNST hybrids not only keep the excellent dendritic fibrous morphology but also bear ca.21 wt%catalytic titanium oxide of anatase crystalline structure.The DFNST-based sensor exhibits extremely strong CTL emission at 440 nm toward diethyl ether against other VOCs like acetone,ethyl acetate,butanol,and so forth.The high response can be attributed to the unique architectural texture of DFNST.Under the optimum parameters,ether could be easily detected in a wide range from 2.0 to 40.0 m M with a fine detection limit of 1.55 m M(S/N=3).Furthermore,the working life of this CTL sensor is satisfactory with outstanding stability and durability,far from damaging the morphology and activity of the DFNST sensing material.In conclusion,it is expected that this novel sensing material,the relevant CTL sensor,and the approach of employing the bandpass filter will be significant for the detection of diethyl ether in actual applications.