Fig. 5: The XPS spectra of Fe 2p.
From: Transformation of siderite to goethite by humic acid in the natural environment
The survey and high-resolution scans of XPS spectra of siderite after reacting with HA and H2O2. a Total survey scans of Fe 2p; b Fe 2p peaks of siderite; c Fe 2p peaks of siderite-HA; d Fe 2p peaks of siderite-H2O2. Samples were freeze-dried for 12 h after 7 days of aging.
