Figure 7From: Effects of acid on the microstructures and properties of three-dimensional TiO2 hierarchical structures by solvothermal methodOptical absorption (a) and diffuse reflectance spectra (b) of 3D TiO 2 structures. Structures synthesized with various acid conditions: 0.68 M HCl, 0.90 M HCl, 1.12 M HCl, 1.35 M HCl, 0.90 HNO3, and 0.90 M HAc, respectively.Back to article page