Interfacial Doping of Heteroatom in Porous SnO₂ for Highly Sensitive Surface Properties

Abstract

The design and synthesis of heteroatom-doping porous materials with unique surface/interfaces are of great significance for enhancing the sensitive surface performance in the fields of catalytic energy, especially gas sensor, CO oxidation, and ammonium perchlorate decomposition. Usually, the template method followed by a high-temperature calcination process is considered as the routes of choice in preparing ion-doped porous materials, but it requires extra templates and will undergo complicated steps. Here, we present a simple fusion/diffusion-controlled intermetallics-transformation method to synthesize various heteroatom-doping porous SnO 2 only by changing the species of intermetallics. By this new method, Ni-doped popcornlike SnO 2 with plenty of ∼30 nm pores and two kinds of Cu-doped SnO 2 nanocages was successfully constructed. Phase-evolution investigations demonstrated that growth kinetics, diffusion, and solubility of the intermediates are highly related to the architecture of final products. Moreover, low-solid-solution limit of MO x (M: Ni, Cu) in SnO 2 made the ion dope close to the surface to form a special surface/interfaces structure, and selective removal of MO x produce abundant pores to increase the surface area. As a consequence, Ni-doped composite exhibits higher sensitivity in formaldehyde detection with a relative low-operating temperature in a short response time (i.e., 23.7–50 ppm formaldehyde, 170 °C, and 5 s) and Cu-doped composites show excellent activity in decreasing the catalytic temperature of CO oxidation and ammonium perchlorate decomposition. The fusion/diffusion-controlled intermetallics-transformation method reported in this work could be readily adopted for the synthesis of other active heteroatom-doping porous materials for multipurpose uses.

Designing SnO2 Nanostructure-Based Sensors with Tailored Selectivity toward Propanol and Ethanol Vapors

“…The high surface to volume ratio and density of surface active sites are supportive of the adsorption and desorption of C 3 H 7 OH gas molecules and surface interaction. 51−54 The hollow sphere structure reduces the path of gas diffusion and enables the penetration of gas molecules.…”

Supramolecular Aggregation-Induced Emission Gels Based on Pillar[5]arene for Ultrasensitive Detection and Separation of Multianalytes

“…Cations and anions play fundamental role in chemistry, environmental science, and other fields; , however, ions pollution is also a serious issue. − For instance, some cations such as Hg 2+ shows strong toxicity for the human body and causing serious illness such as kidney failure, nervous system damage, and endocrine and central nervous system damage of humans and animals; − therefore, the detection and separation of these ions is vital important. , Meanwhile, anions also play significant role in ensuring the good human health, besides biological and environmental systems. − For example, fluoride ions (F – ) are relevant to health care and play a beneficial role in preventing dental health and osteoporosis. − Hence, ultrasensitive detect and separate different ions in the environment has become more and more important.…”

Microstructure and Optical Properties of Nanostructural Thin Films Fabricated through Oxidation of Au–Sn Intermetallic Compounds

“…In the literature, different kinds of structures were reported: molecular sieves [20], hollow nanocages or spheres [21,22], yolk-shell systems [23,24], and hierarchical structures composed of well-mannered low-dimensional sub-units [25]. Unfortunately, in many cases, various practical factors, e.g., the necessity of using templates, significantly complicate the process of fabrication of desirable materials [1]. The template method is usually coupled with a high-temperature calcination that not only complicates the synthetic route, but may also adversely affect the functionality of the synthesized system.…”

“…Semiconducting metal oxide nanostructures (SMONs) with a large specific surface area have many active sites that allow them to work as effective catalysts [ 1 , 2 ], active materials in gas-sensing devices [ 3 , 4 ], electrode materials for lithium ion batteries [ 5 ], or dye-sensitized solar cells [ 6 ]. SMONs based on the transition metal oxides, such as CuO, SnO , ZnO, TiO , Fe O , In O , Co O , and WO , in the form of nanorods, nanoparticles, nanowires, nanospheres, nanosheets, nanotubes, and mesoporous nanostructures [ 3 , 7 , 8 , 9 ] are used especially in gas-sensing applications.…”

“…Simultaneously, the extensive surfaces of oxides (especially heteroatom-doped oxides) are great platforms for catalytic reactions because most of them depend strongly on the structure of the surfaces and interfaces [ 1 , 16 , 17 ]. Therefore, materials with porous architectures [ 3 ] or hierarchical nanostructures [ 18 ] and with large specific surface areas can substantially increase their surface activity sites to create excellent catalytic materials for environmental and energy applications [ 17 , 19 ].…”