. 2023 Feb 1;28(3):1387. doi: 10.3390/molecules28031387

Table 4.

The rate constant and regression coefficient (R²) values of Congo Red and 4-nitrophenol degradation using different rate laws models.

Chemical Kinetics Model	Linear Equation ^a	Nanoparticles	Congo Red		4-Nitrophenol
Chemical Kinetics Model	Linear Equation ^a	Nanoparticles	Regression Coefficient (R²)	Rate Constant (k) ^b	Regression Coefficient (R²)	Rate Constant (k)^b
Zero-order	A₀ − A_t = kt	SPA-AgNPs	0.9131	0.0636	0.9281	0.0384
Zero-order	A₀ − A_t = kt	SPR-AgNPs	0.9369	0.0904	0.9162	0.0665
First-order	$\ln (\frac{A_{0}}{A_{t}}) = kt$	SPA-AgNPs	0.7235	0.0749	0.8836	0.0263
First-order	$\ln (\frac{A_{0}}{A_{t}}) = kt$	SPR-AgNPs	0.8885	0.1514	0.8953	0.0490
Second-order	$\frac{1}{A_{t}} - \frac{1}{A_{0}} = kt$	SPA-AgNPs	0.4812	0.1457	0.8244	0.0189
Second-order	$\frac{1}{A_{t}} - \frac{1}{A_{0}} = kt$	SPR-AgNPs	0.7525	0.4436	0.8675	0.0407

^a A₀—absorbance at the beginning of the reaction; A_t—absorbance at different times (t) of the reaction; ^b k is expressed in mol L⁻¹ min⁻¹ for zero-order kinetics, min⁻¹ for first-order kinetics, and L mol⁻¹ min⁻¹ for second-order kinetics.