One-Step Synthesis of Spherical γ-Fe₂O₃ Nanopowders and the Evaluation of Their Photocatalytic Activity for Orange I Degradation

Table 1

Rate constants () of γ-Fe₂O₃ prepared under different conditions for Orange I photodegradation.

γ-Fe2O3 prepared under different conditions	Rate constants (k) (×10^−3 min^−1)	Relative coefficient ()
Different pH values at 60°C for 6 h
pH 6.0	4.1	0.948
pH 7.0	3.5	0.919
pH 8.0	3.2	0.942
pH 9.1	2.9	0.959
pH 10.1	2.6	0.970
pH 12.1	2.2	0.962
Different reaction temperature at pH 6.0 for 6 h
60°C	4.1	0.948
70°C	3.9	0.959
80°C	3.7	0.959
90°C	3.4	0.971
Different reaction time at 60°C and pH 6.0
6 h	4.1	0.948
10 h	3.1	0.951
16 h	2.6	0.981