Self-Enhanced Antibacterial and Antifouling Behavior of Three-Dimensional Porous Cu₂O Nanoparticles Functionalized by an Organic-Inorganic Hybrid Matrix

Cu2O is currently an important protective material fordomestic engineering and equipment used to exploit marine resources.Cu+ is considered to have more effective antibacterialand antifouling activities than Cu2+. However, disproportionationof Cu+ in the natural environment leads to its reducedbioavailability and weakened reactivity. Novel and functionalizedCu(2)O composites could enable efficient and environmentallyfriendly applications of Cu+. To this end, a series ofthree-dimensional porous Cu2O nanoparticles (3DNP-Cu2O) functionalized by organic (redox gel, R-Gel)-inorganic(reduced graphene oxide, rGO) hybrids R3DNP-Cu2O/rGO( x )@R-Gel Rat room temperature by immobilization-reductionmethod was prepared and applied for protection against marine biofouling.3DNP-Cu2O/rGO(1.76)@R-Gel includes rGO and R-Gelshape 3D porous Cu2O nanoparticles with diameters & SIM;177nm and strong dispersion and antioxidant stability. Compared withcommercial Cu2O (Cu2O-0), 3DNP-Cu2O/rGO(1.76)@R-Gel exhibited an & SIM;50% higher bactericidalrate, & SIM;96.22% higher water content, and & SIM;75% lower adhesionof mussels and barnacles. Moreover, 3DNP-Cu2O/rGO( x )@R-Gel maintains the same excellent, stable, andlong-lasting bactericidal performance as Cu2O-0@R-Gel whilereducing the average copper ion release concentration by & SIM;56to 76%. This was also confirmed by X-ray diffraction, X-ray photoelectricspectroscopy (XPS), atomic absorption spectroscopy, and antifoulingtests. In addition, XPS tests of rGO-Cu2+ and R-Gel-Cu2+, photocurrent tests of 3DNP-Cu2O/rGO(1.76)@R-Gel, and energy-dispersive spectrometry pictures of bacteria confirmthat R-Gel and rGO act as electron donors and transfer substratesdriving the reduction of Cu2+ (Cu2+ & RARR;Cu+) and the diffusion of Cu+. Thus, a self-growingantibacterial and antifouling system of 3DNP-Cu2O/rGO(1.76)@R-Gel was achieved. The mechanism of accelerated bacterialinactivation and resistance to mussel and barnacle adhesion by 3DNP-Cu2O/rGO(1.76)@R-Gel was interpreted. It is shown thatrGO and R-Gel are important players in the antibacterial and antifoulingsystem of 3DNP-Cu2O/rGO(1.76)@R-Gel.