Table 2. Presents the values of zeta potential for cellulose and WO₃ NWs-based membranes at a pH of 7.0.

Sample	Zeta (ζ) potential (mV)
Cellulose	−32.2 ± 1.1
WO3 NWs–cellulose	−21.4 ± 0.8
WO3 NWs–Fe2O3–cellulose	−14.5 ± 0.5
WO3 NWs–CuO–cellulose	−7.6 ± 0.3