Photocatalysis is a field that is swiftly advancing, utilizing the power of light to facilitate chemical reactions. Structural, chemical, and optical properties are critical to the efficiency and efficacy of photocatalysts. This review offers a thorough examination of the diverse characterisation methods that are implemented in photocatalysis, with a particular emphasis on the optical, chemical, electrochemical, morphological, and structural characteristics of photocatalysts. The surface morphology and crystal structure of photocatalysts are characterized using various morphological and structural analysis techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) are utilized to analyze the chemical state and surface composition. Insights into the electronic structure and bandgap properties are obtained through structural analysis techniques, including ultraviolet photoelectron spectroscopy (UPS), low-energy ion scattering spectroscopy (LEIPS), XPS valence band (XPS-VB), and Mott-Schottky measurements. The electrochemical behavior and charge transfer mechanisms are investigated through various electrochemical analysis techniques, such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and transient photocurrent (TPC) measurements. The absorption and emission properties of photocatalysts are examined using optical property analysis techniques, including diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) measurements. This review highlights the importance of these characterization techniques in understanding the properties and behaviors of photocatalysts, which will ultimately aid in the development of more efficient and effective photocatalytic systems for diverse applications.