I am trying to follow this paper (www.sciencedirect.com/science/article/pii/S2405829717301502) to deposit Ni on CuNWs membrane. However, after preparation, CuNWs membrane is hydrophobic. I annealed it at 450oC for 4h in Ar flow. It then became hydrophilic but was scaled down and oxidized partially. Do you have any suggestions?