Table 1: Comparative results obtained for MO degradation and decolorization by various methods.

Degrading systemReaction conditionsObservationsReferences

Gold silver nanocore/silica nanoshell (photocatalytic system)catalyst] = 500 mg L−1
MO] = 50 ppm 
Size (SiO2 = 30 nm)  
(Core shell Ag NPs = 20 nm)  
(Core shell Au NPs = 15 nm)
= 0.01 ± 0.001, 0.023 ± 0.0002, 0.035 ± 0.0005 min−1 for SiO2,  
Au NPs and Ag NPs, respectively  
100% degradation after 120, 70, and 65 min for SiO2, Au NPs, and Ag NPs, respectively
[35]

Nanosized ZnO
(photocatalyst)
ZnO] = 2.5 g L−1 (calcined at  
550°C for 120 min)  
MO] = 5 to 50 mg L−1
Average size = 20 nm
= 0.0631 ± 0.00035 min−1
100% degradation after 120 min
[36]

GT-Fe NPs
(fenton-like catalyst)
GT-Fe NPs] = 50.0 mg 
H2O2] = 5.0 mL of 10.0% 
MO] = 50.0 mg L−1
Size 40–60 nm range
= 0.019 ± 0.0002 min−1
100% degradation after 360 min
[37]

Nanoscale zerovalent Iron Particles (NZVI)NZVI] = 3 g L−1
MO] = 11.4 mg L−1
Size 50–100 nm
= 0.34 ± 0.004 min−1
= 23 ± 1.5 kJ mol−1
100% degradation after 24 min
[38]

Electrochemical-assisted photodegradation on TiO2 thin filmsTiO2] = 2.0 mg 
MO] = 10 ppm
= 0.219 ± 0.00025 min−1
= 18.63 ± 3.5 kJ mol−1
100% degradation after 120 min
[39]

In this studyCu NPs], Cu NRds] = 0.1 mg 
MO] = 100 uM 
NaBH4] = 10 mM 
Size: Cu NPs = (average width = 20 nm and average height = 3.7 nm)  
Cu NRds = (average width = 48 nm and average height = 14 nm)
Cu NPs] = = 0.032 ± 0.001 s−1
= 21 ± 1.0 kJ mol−1100% degradation after 80 sec 
Cu NRds] = = 0.056 ± 0.0015 s−1
= 33 ± 1.2 kJ mol−1
100% degradation after 120 s