2.2. CharacterizationX-ray diffraction (XRD) patterns were observed on a RigakuDmax X-ray diffractometer using Cu K radiation. BET surface areawas measured on ASAP2020 using N2adsorption at −196◦C. Ramanspectra were recorded on a Renishaw inVia Raman microscopeusing an excitation of 632 nm laser light. Transmission electronmicroscopy (TEM) images were obtained on a JEM-100CX electronmicroscope. XPS spectra were obtained by a VG Multilab 2000 X-rayphotoelectron spectrometer using Mg K radiation, and calibratedby referencing the binding energy to adventitious carbon (C1s284.6 eV). Diffuse reflectance UV–vis–IR (DRUV–vis–IR) absorptionspectra were recorded on a UV-3600 spectrophotometer. Photolu-minescence spectra (PL) were recorded at room temperature on aQM/TM/NIR spectrofluorometer (PTI) by using 337 nm and 480 nmexcitation