Systematic and detailed examination of NaYF4-Er-Yb-TiO2 photocatalytic activity under Vis–NIR irradiation: Experimental and theoretical analyses

A UV-visible-NIR active smart photocatalytic system based on NaYbF4:Tm3+ upconverting particles and Ag3PO4/H2O2 for photocatalytic processes under light on/light off conditions

“…Photoexcitation of the photocatalysts and interband transitions then result in the production of oxidative holes in the valence band (VB) and reductive electrons in the conduction band (CB) for the subsequent redox reaction on the photocatalyst's surface responsible for degradation of pollutants 45,53,54 . Despite the theoretical feasibility of the NIR active UCPs/Photocatalysts system, reported literature on the topic indicates limited practical success and lower contaminants removal efficiency of the system, often requiring several hours of NIR illumination [54][55][56][57][58] . The combination of different advanced oxidation processes such as photocatalysis and Fenton-like process using H 2 O 2 as an oxidizing agent, is a possible strategy to address the problem of low photoactivity under NIR irradiation [59][60][61] .…”

“…45,53,54 Despite the theoretical feasibility of the NIR active UCPs/photocatalyst system, reported literature on this topic demonstrates the limited practical success and lower contaminant removal efficiency of the system, often requiring several hours of NIR illumination. [54][55][56][57][58] The combination of different advanced oxidation processes such as photocatalysis and Fenton-like processes using H 2 O 2 as an oxidizing agent is a possible strategy to address the problem of low photoactivity under NIR irradiation. [59][60][61] In this work, we report a smart photocatalytic system based on NaYbF 4 :Tm 3+ UCPs/Ag 3 PO 4 /H 2 O 2 that can be activated under both direct visible light illumination from low-cost blue LEDs (460 AE 10 nm) as well as NIR illumination, thanks to the NIR-to-UV/visible upconversion by the UCPs.…”

Laser Refrigeration by an Ytterbium‐Doped NaYF4 Microspinner

“…[ 5,6 ] Their physical properties, including their nonstoichiometric composition, [ 7,8 ] are well‐studied and they are being used in a wide range of applications including bioimaging, [ 9,10 ] remote sensing, [ 11–14 ] imaging displays, solar cells [ 15–17 ] and photocatalysis. [ 18,19 ] Most of these applications are based on the good fluorescent properties (i.e., high (photo)stability, high brightness, spectral purity and long fluorescence lifetimes) of lanthanide ions in the NaYF 4 lattice. [ 20 ] After optical excitation, lanthanide ions in NaYF 4 undergo relaxation to their ground state by involving both radiative and nonradiative de‐excitations.…”

Functional Materials with Wide‐Spectral‐Responsive Photocatalytic Activity and Real‐Time Temperature Feedback: The Electrospun Fibers Embedded with NaGdF4‐Tm‐Yb@TiO2 Nanocrystals

“…[34][35][36][37][38][39] Thence, it is reasonable and feasible that the bright fluorescence emitted by the RE 3+ doped fluoride is reabsorbed by TiO 2 semiconductor for the photocatalytic reaction. [40] Qin et al synthesized the NaYF 4 :Yb 3+ , Tm 3+ @TiO 2 nanoparticles In this work, combining the advantages of upconversion materials, nanofibers, and TiO 2 semiconductors, the composite fibers embedded with NaGdF 4 : Tm 3+ , Yb 3+ @TiO 2 nanocrystals (NGF-TY@TiO 2 NCs) are prepared as wide-spectral (UV-NIR) response photocatalysts and temperature sensing materials. Based on the FIR technique, both the thermally ( 3 F 2,3 and 3 H 4 ) and nonthermally ( 1 G 4 and 3 F 2,3 ) coupled levels of Tm 3+ are confirmed to be applicable as temperature probes for real-time monitoring and feedback of the working temperature of the catalytic degradation process, and the maximum relative sensitivity values of S R1 and S R2 are as high as 2.760%K −1 and 3.019%K −1 at 304 K, respectively.…”