TiO_(2)基水凝胶在光催化中的应用:最新进展和未来前景

二氧化钛(TiO_(2))半导体在光催化领域具有广阔的应用前景,但也存在着诸多问题,包括光生电子-空穴对的快速复合和太阳能利用效率低等。将TiO_(2)嵌入到一系列功能性水凝胶中形成的TiO_(2)基水凝胶展现出了稳定的三维多孔骨架、较高的介孔率、大的比表面积、适当的孔体积和较高的亲水性,使其光催化效率得到大幅度提升。本文首先概括了TiO_(2)基水凝胶的结构特征及合成方法。TiO_(2)作为填料,被引入到石墨烯基水凝胶,聚合物基水凝胶和多组分复合水凝胶三个体系中;而且,作为交联剂,可分别以纳米颗粒和纳米片的形态参与水凝胶的制备和合成过程。其次,对近年来TiO_(2)基水凝胶在废水净化、水裂解和灭菌三方面的光催化研究进展进行了总结。最后,对该复合材料目前存在的一系列问题进行了深刻探讨并提出了初步的解决方案。

Gas sensors based on TiO_(2) nanostructured materials for the detection of hazardous gases: A review

Hazardous gases have been strongly associated with being a detriment to human life within the environment The development of a reliable gas sensor with high response and selectivity is of great signifcance for detecting different hazardous gases.TiO_(2) nanomaterials are promising candidates with great potential and excellent per-formance in gas sensor applications,such as hydrogen,acetone,ammonia,and ethanol detection.This review begins with a detailed discussion of the di ferent dimensional morphologies of TiO_(2),whitch affect the gas sensing performance of TiO_(2) sensors.The diverse morphologies of TiO_(2) can easily be tuned by regulating the manufacturing conditions.Meanwhile,they exhibit unique characteristics for detecting gases,including large specific suface area,superior elecron tr ansport rates,extraordinary pemmeability,and active reaction sites,which offer new opportunities to improve the gas sensing properties.In addition,a variety of efforts have been made to functional TiO_(2) nanomaterials to further enhance sensing properties,including TiO_(2)-based composites and light-assisted gas sensors.The enhanced gas sensing mechanisms of multi-component composite nano-materials based on TiO_(2) include loaded noble metals,doped elements,constructed heterojunctions,and com-pounded with other functional materials.Finally,several studies have been summarized to demonstate the compar ative sensing properties of TiO_(2)-based gas sensors.

Floatable Fe-TiO_(2)/hydrogel composite for photodegradation of water pollutants

The development of highly efficient and low-cost photocatalysts for degradation of organic pollutants become an effective approach for environmental remediation.However,the practical application of traditional powder catalyst in photocatalytic technology is limited due to its low recycling capacity,agglomeration and secondary pollution risk.Herein,a floating Fe-doped TiO_(2) and hydrogel(FTH)composite was synthesized for the photodegradation of Rhodamine B via a facile impregnation method.The photodegradation results show that the FTH composite exhibits a higher photocatalytic efficiency with degradation percentage(95.6%)compared with pure TiO_(2)(41.2%).The enhanced photocatalytic performance is attributed to its excellent flotation performance,providing a large number of active sites for pollutant degradation,contact with O_(2) and photons at the air/water interface.Remarkably,the adsorbed Rhodamine B in FTH can still be removed by exposing to light in the air alone,demonstrating strong recovery ability of the FIH composite catalyst.The floatable hydrogel nanocomposites offer a promising solution for scalable solar-drive degradation of water pollutants,paving the way for sustainable water treatment technologies.

Reversible Zn^(2+) Insertion in Tungsten Ion-Activated Titanium Dioxide Nanocrystals for Electrochromic Windows

Zinc-anode-based electrochromic devices(ZECDs) are emerging as the next-generation energy-e cient transparent electronics. We report anatase W-doped TiO_(2) nanocrystals(NCs) as a Zn^(2+) active electrochromic material. It demonstrates that the W doping in TiO_(2) highly reduces the Zn^(2+) intercalation energy,thus triggering the electrochromism. The prototype ZECDs based on W-doped TiO_(2) NCs deliver a high optical modulation(66% at 550 nm),fast spectral response times(9/2.7 s at 550 nm for coloration/bleaching),and good electrochemical stability(8.2% optical modulation loss after 1000 cycles).

Ordered macroporous structured TiO_(2)-based photocatalysts for CO_(2)reduction:A review

Herein,we review the significant of ordered macroporous(OM)TiO_(2)-based catalysts for boosting pho-tocatalytic CO_(2)reduction.Based on the need to improve the three key factors of photogenerated charge separation eficiency,solar energy utilization and CO_(2)adsorption rate during the conversion of CO_(2)to H_(2)O,we summarized five modification measures:including doping ions into OM TiO_(2),introducing sec-ond semiconductor coupling and noble metal nanoparticles for fabricating multiple Z-scheme heterojunc-tions,constructing hierarchical pore and carbon-loaded OM TiO_(2)materials,which effectively enhance the absorption rate of visible light,the separation rate of electrons-hole pairs and the selection of multiple active sites.The OM structured TiO_(2)-based photocatalysts solve the single or multiple key factors for en-hancing photocatalytic performances during CO_(2)conversion.The catalytic mechanism and pathways of OM structured TiO_(2)-based photocatalysts for CO_(2)reduction are discussed and summarized.It provides new insights on the development of high-efficient catalyst for photocatalytic CO_(2)conversion to solar fu-els.

石墨烯量子点-TiO_(2)/聚丙烯酰胺荧光水凝胶的制备与性能

通过将原位溶胶-凝胶法和自由基聚合法巧妙相结合制备了一种坚固、荧光的杂化水凝胶石墨烯量子点-TiO_(2)/聚丙烯酰胺(GQDs-TiO_(2)/PAM)。在该杂化水凝胶中,同时充当多功能交联剂和纳米填料的TiO_(2)和GQDs粒子与水凝胶网络中的亲水基团通过氢键等非共价键牢固地结合。PAM、TiO_(2)和GQDs之间的强非共价键作用赋予该凝胶优异的力学性能。GQDs-TiO_(2)/PAM(0.5wt%GQDs)水凝胶的断裂伸长率和抗拉强度分别高达2412%和181 kPa,为TiO_(2)/PAM水凝胶的1.78和1.13倍。另外,GQDs的引入还赋予该复合水凝胶特殊的荧光性能,它能够在365 nm紫外光照射下发出明显的蓝色荧光。因此,该水凝胶在生物医药、重金属离子检测、荧光探针等领域有很大发展潜力。