A series of Cu(OH)2/g-C3N4 photocatalysts were fabricated via precipitation and sonoprecipitation. Various physicochemical and electrochemical techniques were employed to investigate the physical and optical properties of the samples, while their photocatalytic performance was studied based on the water splitting. Based on the observations, Cu(OH)2 was nominated as an stable and highly efficient non-precious cocatalyst for photocatalytic H2 generation. 4Cu(OH)2/C3N4(U) sample demonstrated the highest performance (187 μmol/h/g) among the other samples with various loading of Cu(OH)2 which is 31 times higher than pure C3N4. This enhancement was because of the important role of Cu(OH)2 as electron traps and active sites. Additionally, the photoactivity of the sono-synthesized photocatalyst was significantly higher than the one synthesized by precipitation method by 67%. The findings confirmed the promoting influence of ultrasound irradiation on providing well intimate cocatalyst-semiconductor interfacial contact, higher surface area and better dispersion of cocatalysts. This could facilitate the efficient transfer of electrons to cocatalyst and decrease charge carriers recombination where supported by PL, EIS and transient photocurrent results. This study addresses the sonochemical method as a promised rout for fabrication of a closely contact interface which is a key parameter to achieve more efficient noble metal free cocatalysts.

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