Optimization of photocatalytic degradation of methyl orange using immobilized scoria-Ni/TiO2 nanoparticles Meghdad Pirsaheb, Hiwa Hossaini, Simin Nasseri, Nahid Azizi*, Behzad Shahmoradi, Toba Khosravi, 10.1007/s40097-020-00337-x XML