Nickel hydroxide β-Ni(OH)2 hexagonal nanosheets were synthetized via a hydrothermal exfoliation process. The practical microwave-assisted hydrothermal method facilitated obtaining layered nickel 3D nanoplates with cerium functionalization in 5 h. The as-produced nanostructures were characterized by XRD, XPS, FESEM, FTIR, PL, UV-vis, and BET techniques. The hydroxilated structures are nano-thick hexagonal plates with sides 28 nm in length and an average thickness of 5 nm. UV and PL irradiation was used to study the photoactive properties in the degradation of a pharmaceutical emerging pollutant, naproxen. UV-vis spectroscopy and high-performance liquid chromatography monitoring indicated that the Ni(OH)2-Ce nanostructures are an effective photocatalyst for naproxen degradation, including 40% mineralization of this highly recalcitrant drug. The photocatalyst showed stability for two consecutive cycles, preserving its photoactive and structural characteristics. Ce3+-doped nanoplates and surface functionalized Ce4+ act as charge separators and scavenging agents for the enhanced photodegradation of naproxen.