Recent research progress on mixed valence state tungsten based materials

Meng

Adv Energy and Sustain Res

et al. 2021

Energy consumption of buildings during heating and cooling accounts for about 15% of global total energy consumption. Advanced dynamic switchable windows that enable independent control of solar heat will contribute to optimal energy efficiency in heating, cooling, and artificial lighting systems throughout buildings. Recently, energy‐efficient plasmonic electrochromic smart windows (PESWs) based on metal oxide nanocrystals (NCs) have been gaining increasing attention due to their effective and controllable regulation over the near‐infrared region of the solar spectrum without affecting the dynamic visible transmittance of the smart windows. Herein, the current state‐of‐the‐art results of colloidal metal oxide NCs for PESWs are highlighted, along with their design strategies and working principles. The recent research status of PESWs in typical colloidal metal oxide NCs is reviewed in detail, and the challenges and corresponding countermeasures in this field are discussed. Furthermore, an outlook into novel opportunities in PESW‐related academic research and how to accelerate the pace of real‐world applications is presented.

Section: Overview Of Plasmonic Metal Oxide Ncsmentioning

confidence: 99%

Advances in Energy‐Efficient Plasmonic Electrochromic Smart Windows Based on Metal Oxide Nanocrystals

Meng

Adv Energy and Sustain Res

et al. 2021

“…Moreover, the use of near-infrared (NIR; 750–1000 nm) light as a trigger for the photothermal therapy avoids the radiation interaction with the different biological constituents achieving a high tissue penetration [ 7 , 8 ]. In this way, several types of nanomaterials, such as those based on gold, carbon (e.g., carbon nanotubes, nanographene oxide), copper, tungsten, iron and molybdenum, have been under extensive study to mediate the cancer photothermal therapy [ 9 , 10 , 11 , 12 , 13 , 14 ]. Among them, the unique physicochemical properties of gold-based nanomaterials highly support their application as promising photothermal therapeutic agents [ 7 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

Optimization of the GSH-Mediated Formation of Mesoporous Silica-Coated Gold Nanoclusters for NIR Light-Triggered Photothermal Applications

et al. 2021

Cancer light-triggered hyperthermia mediated by nanomaterials aims to eliminate cancer cells by inducing localized temperature increases to values superior to 42 °C, upon irradiation with a laser. Among the different nanomaterials with photothermal capacity, the gold-based nanoparticles have been widely studied due to their structural plasticity and advantageous physicochemical properties. Herein, a novel and straightforward methodology was developed to produce gold nanoclusters coated with mesoporous silica (AuMSS), using glutathione (GSH) to mediate the formation of the gold clusters. The obtained results revealed that GSH is capable of triggering and control the aggregation of gold nanospheres, which enhanced the absorption of radiation in the NIR region of the spectra. Moreover, the produced AuMSS nanoclusters mediated a maximum temperature increase of 20 °C and were able to encapsulate a drug model (acridine orange). In addition, these AuMSS nanoclusters were also biocompatible with both healthy (fibroblasts) and carcinogenic (cervical cancer) cells, at a maximum tested concentration of 200 μg/mL. Nevertheless, the AuMSS nanoclusters’ NIR light-triggered heat generation successfully reduced the viability of cervical cancer cells by about 80%. This confirms the potential of the AuMSS nanoclusters to be applied in cancer therapy, namely as theragnostic agents.

“…Nevertheless, mixed valence solids, such as oxides based on molybdenum blues and tungsten bronzes, opened a new era in inorganic and then materials chemistry after the pioneering work of Arne Magneli [ 8 , 9 ]. His discoveries of unusual structures and the mixed valence nature of these new phases inspired explosive growth of interest to these new oxides-based phases [ 10 , 11 , 12 , 13 , 14 ]. These new non-stoichiometric systems turned out to be primarily of great importance in electronics as conducting/semiconducting materials [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ] and quite recently in catalysis [ 23 , 24 , 25 , 26 , 27 , 28 ], and nano-technology [ 29 , 30 , 31 ].…”

Section: Introductionmentioning

confidence: 99%

New Solids in As-O-Mo, As(P)-O-Mo(W) and As(P)-O-Nb(W) Systems That Exhibit Nonlinear Optical Properties

et al. 2021

Interactions between well-mixed fine powders of As2O3, P2O5, MoO3, WO3 and Nb2O5 at different stoichiometry in quartz ampoules under vacuum at ~1000 °C in the presence of metallic molybdenum (or niobium), over several weeks, led to shiny dichroic crystalline materials being formed in cooler parts of the reaction vessel. An addition of small quantities of metals-Mo or Nb-was made with the aim of partially reducing their highly oxidized Mo(VI), W(VI) or Nb(V) species to corresponding Mo(V), W(V) and Nb(IV) centers, in order to form mixed valence solids. Sublimed crystals of four new compounds were investigated using a variety of techniques, with prime emphasis on the X-ray analysis, followed by spectroscopy (diffusion reflectance, IR, Raman and EPR), second harmonic generation (SHG), thermal analysis under N2 and air atmosphere, and single crystals electrical conductivity studies. The results evidenced the formation of new complex solids of previously unknown compositions and structures. Three out of four compounds crystallized in non-centrosymmetric space groups and represent layered 2D polymeric puckered structures that being stacked on each other form 3D lattices. All new solids exhibit strong second-harmonic-generation (SHG effect; based on YAG 1064 nm tests with detection of 532 nm photons), and a rare photosalient effect when crystals physically move in the laser beam. Single crystals’ electrical conductivity of the four new synthesized compounds was measured, and the results showed their semiconductor behavior. Values of band gaps of these new solids were determined using diffusion reflectance spectroscopy in the visible region. Aspects of new solids’ practical usefulness are discussed.