Synthesis and structure of new (Bi, La)₃MSb₂O₁₁ phases (M = Cr, Mn, Fe) are reported in conjunction with their magnetic and photocatalytic properties. XRD refinements reflect that Bi₃CrSb₂O₁₁, Bi₂LaCrSb₂O₁₁, Bi₂LaMnSb₂O₁₁ and Bi₂LaFeSb₂O₁₁ adopt KSbO₃-type structure (space group, 𝑃𝑛$\bar{3}$). The structure can be described through three interpenetrating networks where the first is the (M/Sb)O₆ octahedral network and other two are the identical networks having Bi₆O₄ composition. The magnetic measurements on Bi₂LaCrSb₂O₁₁ and Bi₂LaMnSb₂O₁₁ show paramagnetic behaviour with magnetic moments close to the expected spin only magnetic moments of Cr⁺³ and Mn⁺³. The UV-Visible diffuse reflectance spectra are broad and indicate that these materials possess a bandgap of ∼ 2 eV. The photocatalytic activity of these materials has been investigated by degrading Malachite Green (MG) under exposure to UV light.

Layered LiNi_0.8Co_0.2O₂ crystallizing in 𝑅$\bar{3}$𝑚 space group is synthesized by decomposing the constituent metal–nitrate precursors. Oxidizing nature of metal nitrates stabilizes nickel in +3 oxidation state, enabling a high degree of cation ordering in the layered LiNi_0.8Co_0.2O₂. The powder sample characterized by XRD Rietveld refinement reveals < 2% Li–Ni site exchange in the layers. Scanning electron microscopic studies on the as-synthesized LiNi_0.8Co_0.2O₂ sample reflect well defined particles of cubic morphology with particle size ranging between 200 and 250 nm. Cyclic voltammograms suggest that LiNi_0.8Co_0.2O₂ undergoes phase transformation on first charge with resultant phase being completely reversible in subsequent cycles. The first-charge-cycle phase transition is further supported by impedance spectroscopy that shows substantial reduction in resistance during initial de-intercalation. Galvanostatic charge–discharge cycles reflect a firstdischarge capacity of 184 mAh g^-1 which is stabilized at 170 mAh g^-1 over 50 cycles.