Fig. 5From: Preparation of Hollow Polyaniline Micro/Nanospheres and Their Removal Capacity of Cr (VI) from Wastewatera–c Element mapping and d Cr 2p XPS spectra of the hollow PANI micro/nanospheres after reaction with Cr (VI) (initial Cr (VI) concentration: 1.2 mmol/L (62.4 mg/L); solution pH respectively at 3, 4, and 5)Back to article page