Nir-driven plasmon-enhanced composite upconversion photocatalyst β-NaLuF4@NaLuF4:Yb3+, Tm3+@Ag@BiOBr for photocatalytic pollutant degradation

The infrared energy of the sun’s rays accounts for more than 40 %. Heterostructures were constructed to enable broad-spectrum response of photocatalysts, and enhance the utilization of sunlight, especially that of infrared lights. A robust heterostructured upconversion composite material decorated with Ag nanoparticles (AgNPs), β-NaLuF 4 @ NaLuF 4 :Yb 3+ ,Tm 3+ @ AgNPs@BiOBr (NLF@NLFT@Ag@Bi), was built through a multi-step hydrothermal method. NLF@NLFT@Ag@Bi demonstrates enhanced photocatalytic activity under UV–Vis-NIR, Vis-NIR, and NIR irradiation compared to pure BiOBr and NLF@NLFT@Ag/BiOBr mixture, achieving 99 % Rhodamine B (RhB) degradation in 0.5 h (UV–Vis-NIR) and 96 % in 3 h (NIR), with degradation over 80 % for Bisphenol A (BPA), Norfloxacin (Nor), and Methyl Orange (MO) in 3 h (UV–Vis-NIR). The upconversion luminescence (UCL) of NLF@NLFT@Ag is tuned by its core–shell structure and AgNPs’ plasmonic effect, while NLF@NLFT@Ag@Bi’s enhanced photocatalysis arises from boosted UCL and AgNPs-facilitated Förster resonance energy transfer (FRET) between NLFT and BiOBr. The material’s efficacy in infrared-driven photocatalysis offers a prospective approach for extending catalyst response ranges. It greatly enhances degradation effects of organic pollutants under sun’s rays.