The development of effective catalysts for the catalytic conversion of the harmful nitrophenol (NP) into the useful aminophenol (AP) has received extensive interest. Herein, we report the easy and large-scale synthesis of strongly coupled Ag/TiO₂ heterojunctions based on the coordinated action of organic components with a multi-kind metal precursor. The heterojunctions were effective and stable catalysts for the photothermal catalytic reduction of 4-NP to 4-AP. In the synthesis, critic acid, ethylene glycol, AgNO₃, and tetrabutyl titanate were dissolved and coordinated in water. Under heating, a precursor gel having a uniform distribution of Ag and Ti was gradually formed. Via calcination in air, the Ti precursor was transformed into TiO₂, accompanied by the reduction of Ag⁺ to Ag nanoparticles. The formation of Ag/TiO₂ composites with intimate interface contact benefited from the uniform distribution of different components in the precursor gel. The Ag/TiO₂ functioned as an effective catalyst for the reduction of 4-NP, exhibiting higher activity than the many reported Ag-based catalysts. The catalytic reaction over Ag/TiO₂ had a small t₀ with good activity and reuse performance. After 10 cycles of reuse, the conversion efficiency exhibited no obvious change. Importantly, the conversion of 4-NP was significantly enhanced under light irradiation provided by a 150-W Xe lamp (the visible light from cutoff have equal function), but ultraviolet light did not promote the conversion. The conversion time was reduced from 620 to 270 s with light irradiation (15 ℃). The reaction rate under light irradiation (0.014 s^-1) was approximately three times higher than that in the dark at 15 ℃ (0.0044 s^-1) and even better than that in the dark at 25 ℃ (0.01 s^-1). A series of experiments indicated that the light irradiation promoted the conversion of 4-NP because of the localized surface plasmon resonance effect of Ag, which generated hot e^- and h⁺ particles and local heating around the particles via their absorption of the light.