Self-Enhanced Antibacterial and Antifouling Behavior of Three-Dimensional Porous Cu<sub>2</sub>O Nanoparticles Functionalized by an Organic–Inorganic Hybrid Matrix
Huali Li, Liuqin Zhang, Xiaohu Zhang, Guangyu Zhu, Dongchen Zheng, Shuwen Luo, Min Wu, Weihua Li, Fa‐Qian Liu
Abstract
Cu 2 O is currently an important protective material for domestic engineering and equipment used to exploit marine resources. Cu + is considered to have more effective antibacterial and antifouling activities than Cu 2+ . However, disproportionation of Cu + in the natural environment leads to its reduced bioavailability and weakened reactivity. Novel and functionalized Cu 2 O composites could enable efficient and environmentally friendly applications of Cu + . To this end, a series of three-dimensional porous Cu 2 O nanoparticles (3DNP-Cu 2 O) functionalized by organic (redox gel, R-Gel)–inorganic (reduced graphene oxide, rGO) hybrids─3DNP-Cu 2 O/rGO x @R-Gel─at room temperature by immobilization–reduction method was prepared and applied for protection against marine biofouling. 3DNP-Cu 2 O/rGO 1.76 @R-Gel includes rGO and R-Gel shape 3D porous Cu 2 O nanoparticles with diameters ∼177 nm and strong dispersion and antioxidant stability. Compared with commercial Cu 2 O (Cu 2 O-0), 3DNP-Cu 2 O/rGO 1.76 @R-Gel exhibited an ∼50% higher bactericidal rate, ∼96.22% higher water content, and ∼75% lower adhesion of mussels and barnacles. Moreover, 3DNP-Cu 2 O/rGO x @R-Gel maintains the same excellent, stable, and long-lasting bactericidal performance as Cu 2 O-0@R-Gel while reducing the average copper ion release concentration by ∼56 to 76%. This was also confirmed by X-ray diffraction, X-ray photoelectric spectroscopy (XPS), atomic absorption spectroscopy, and antifouling tests. In addition, XPS tests of rGO-Cu 2+ and R-Gel-Cu 2+, photocurrent tests of 3DNP-Cu 2 O/rGO 1.76 @R-Gel, and energy-dispersive spectrometry pictures of bacteria confirm that R-Gel and rGO act as electron donors and transfer substrates driving the reduction of Cu 2+ (Cu 2+ → Cu + ) and the diffusion of Cu + . Thus, a self-growing antibacterial and antifouling system of 3DNP-Cu 2 O/rGO 1.76 @R-Gel was achieved. The mechanism of accelerated bacterial inactivation and resistance to mussel and barnacle adhesion by 3DNP-Cu 2 O/rGO 1.76 @R-Gel was interpreted. It is shown that rGO and R-Gel are important players in the antibacterial and antifouling system of 3DNP-Cu 2 O/rGO 1.76 @R-Gel.