Synthesis of CdS Sensitized TiO₂ Photocatalysts: Methylene Blue Adsorption and Enhanced Photocatalytic Activities

Table 3

Nonlinear Langmuir, Freundlich, and Sips constants for MB adsorption on different adsorbents obtained from the NL fits shown in Figures 7(b)–7(d).

Isotherm model	Samples
	TiO2	TCd1	TCd2	TCd3	TCd4
Langmuir
, mg MB/g cat.	14.3	14.9	12.0	8.2	7.8
, L/mg MB	0.125	0.030	0.070	0.037	0.035
	0.10	0.25	0.13	0.21	0.22
	0.987	0.099	0.120	0.052	0.010
Freundlich
, mg MB/g (L/mg MB	4.669	1.315	2.574	1.051	0.931
	0.25	0.48	0.32	0.41	0.42
	4.138	0.554	0.418	0.076	0.087
Freundlich-Langmuir (Sips)
, mg MB/g	13.1	14.9	13.3	10.7	8.7
, L/g	0.054	0.030	0.092	0.053	0.043
	0.689	1.000	1.210	1.340	1.148
	0.535	0.099	0.082	0.022	0.003
SSA, m^2 g^−1	29.6	33.7	30.0	24.2	19.6