1：Experimental Design and Method Selection:

A two-step route combining chemical bath deposition (CBD) and hydrothermal methods was used to prepare NiO nanoporous/ZnO nanoarray films on ITO glass substrates. This design leverages the advantages of CBD for easy, low-temperature synthesis and hydrothermal methods for growing aligned nanostructures.

2：Sample Selection and Data Sources:

ITO glass substrates (2 × 2.5 cm2) were used. Samples included ZnO nanoarray (ZnO NA), NiO nanoporous (NiO NP), and ZnO@NiO nanorod array-porous film (ZnO@NiO NAP). Data were sourced from material characterizations and electrochromic performance tests.

3：5 cm2) were used. Samples included ZnO nanoarray (ZnO NA), NiO nanoporous (NiO NP), and ZnO@NiO nanorod array-porous film (ZnO@NiO NAP). Data were sourced from material characterizations and electrochromic performance tests. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Chemicals such as zinc acetate dehydrate, hexamethylenetetramine, nickel sulfate hexahydrate, potassium peroxydisulfate, lithium perchlorate, ammonia solution, hydrochloric acid, ethanol, and 4-hydroxybutanoic acid lactone were purchased from Aladdin Reagent Company. Equipment included a Hitachi HT7700 TEM microscope, Bruker D8 Advance XRD diffractometer, S4800 SEM, Shimadzu UV-3600 spectrophotometer, and CHI660C electrochemical workstation.

4：Experimental Procedures and Operational Workflow:

First, ZnO nanoarray was prepared hydrothermally by spin-coating a seed layer and growing nanorods at 95°C. Then, NiO nanoporous was deposited via CBD by immersing in a solution of NiSO4 and K2S2O8 with ammonia, followed by calcination. EC devices were assembled with the film as the working electrode, an ITO counter electrode, and an electrolyte of LiClO4 in 4-HBAL.

5：Data Analysis Methods:

XRD for crystal structure, SEM and TEM for morphology, UV-vis for optical properties, CV for electrochemical behavior, and transmittance measurements for electrochromic performance. Bandgaps were calculated using Tauc plots, and coloration efficiency was derived from optical density changes.