Chemical compositions and analyses of Mn oxides - transformation from Co-containing vernadite to nsutite and hollandite

This dataset accompanies the Wu et al. manuscript entitled \"Transformation from Co-containing vernadite to nsutite and hollandite: Implications for the retention of Co in Mn Oxides with small tunnel sizes\". The dataset contains: 1) Chemical compositions, 2) XAS data at Mn and Co K-edges, 3) XRD data, and 4) Chemical analyses upon nitric acid treatment.