The objective in this study is to investigate the adsorption-degradation of the methylene blue (MB) dye using a fabricated heterojunction Ag@TiO

2

nanocomposite. The batch factors used in photo catalytic reactions were pH

UV-irradiation time

temperature

catalytic dosage

and concentration of MB. The results showed that 0.2×10

3

g·ml

-1

) of the catalytic dose caused the Ag@TiO

2

adsorption to degrade by 96.67% with darks and UV exposure. Using the Langmuir-Hinshelwood model to determine the kinetic

the Ag@TiO

2

displays a greater kinetic rate than TiO

2

and silver nanoparticle (AgNPs). The photocatalytic degradation of MB

which is an endothermic reaction involving all catalysts

is shown by the thermodynamic parameter to have the positive value of enthalpy (Δ

H

°). The enthalpies observed were Ag@TiO

2

(126.80 kJ·mol

-1

) AgNPs (354.47 kJ·mol

-1

) TiO

2

(430.04 kJ·mol

-1

). Ascorbic acid (

·

OH scavenger)

2-propanol (

·

O

2

scavenger)

and ammonium oxalate (AO) (hole h

+

scavenger) were employed to conduct the scavenger effect

s. The Ag@TiO

2

demonstrated a reduction in MB degradation when combined with 2-propanol

and this clearly demonstrated that

in contrast to hydroxyl radicals (

·

OH) and hole (h

+

) scavengers

superoxide radical anion (

·

O

2

scavenger) plays a significant role in MB degradation. Utilizing density functional theory (DFT) to elucidate the mechanism and B3LYP/6-311+G(d

p) level optimization

the degradation-adsorption process was explained. When the N-N

C-N or C-C bonds were severed

the Fukui faction was demonstrated for nucleophilic

electrophilic

and radical attack.