The X-ray powder diffraction (XRPD) patterns of all BYW samples were collected by using a Rigaku SmartLab X-ray diffractometer in Bragg–Brentano geometry with Cu Kα radiation. The diffracted beam was monochromatized by silicon single crystals and collected by using a D/tex linear detector. The XRPD data were collected over a 2θ range of 10° to 120° with a step size of 0.02°.
High-resolution electron microscopy images were obtained using a Zeiss Ultra Plus High Resolution Field Emission Gun Scanning Electron Microscope (FEGSEM). Energy-dispersive X-ray spectroscopy (EDS) spectra were acquired using an Oxford X-MaxN Silicon drift detector (SDD). The diffuse reflectance spectra of the powders were recorded using a Shimadzu UV 2600 spectrophotometer equipped with an ISR-2600Plus Integrating Sphere Attachment. The Raman spectra were collected using a micro-Raman spectrometer (iHR550, Horiba) with a green laser (λ = 514 nm).
Diffuse reflectance measurements were performed by putting a small amount of sample (50 mg) on top of a BaSO4 tablet and then pressing. Pure BaSO4 was used as a baseline because its reflectance is close to 100% in the examined range (200 nm < λ < 700 nm).
High-resolution electron microscopy images were obtained using a Zeiss Ultra Plus High Resolution Field Emission Gun Scanning Electron Microscope (FEGSEM). Energy-dispersive X-ray spectroscopy (EDS) spectra were acquired using an Oxford X-MaxN Silicon drift detector (SDD). The diffuse reflectance spectra of the powders were recorded using a Shimadzu UV 2600 spectrophotometer equipped with an ISR-2600Plus Integrating Sphere Attachment. The Raman spectra were collected using a micro-Raman spectrometer (iHR550, Horiba) with a green laser (λ = 514 nm).
Diffuse reflectance measurements were performed by putting a small amount of sample (50 mg) on top of a BaSO4 tablet and then pressing. Pure BaSO4 was used as a baseline because its reflectance is close to 100% in the examined range (200 nm < λ < 700 nm).