Spectrophotometric Analysis

2. EXPERIMENTAL DETAILS
2.1 Materials and Method
All the chemicals used were in analytical grade and were used without further purification. In a typical experiment, 0.1 M of copper (II) nitrate trihydrate (Cu(NO3)2.3H2O), 98%;Merck) was dissolved in 350 ml deionized water and allowed to stir for complete dissolution of the compound. 0.05 M of hexamethylenetetramine (HMT) (C6H12N4,ACS reagent, ≥99.0%) was added drop wise to the above solution. The CuO precursors containing Na+-dopant was prepared with 1.0 mole% and 2.0 mole % of sodium nitrate concentration. The resultant solutions was subjected to slow magnetic stirring at 50°C until a uniform light green solutions are formed, indicating the formation of copper hydroxide. 0.2 M of sodium hydroxide

Photoluminescence (PL) spectra within the wavelength range 520–700 nm were recorded under 240 nm line of Xe-laser excitation using F-7000 Hitachi Fluorescence Spectrophotometer.
3. RESULTS AND DISCUSSION
3.1. Structural investigation
The characteristic X-ray diffraction patterns of Pristine and CuO:Na+ with varying Na content were recorded in the range of 2θ between 20º to 80º, and shown in Fig. 1a. All the synthesized samples are found to exhibit similar diffraction peaks. The specific crystallographic planes confirmed that the formation of the CuO (space group C2/c) monoclinic phase matches with the standard JCPDS card No. 80-1916. Furthermore, there is no clear change in peak position as well as the peaks are found to be quite sharp and intense, which implies the high crystallinity of the prepared powders. A careful analysis of the diffraction patterns shows that there is no trace of copper related phase (metallic copper, cuprous oxide or any binary copper sodium phases) for all CuO:Na+ compositions. This indicates that Na ions were successfully doped into the lattice of Cu sites without affecting the crystal structure of the parent CuO matrix. The radius difference between Cu2+ ion (0.73

The peak position systematically shifts towards lower 2θ values with Na doping (shown in the Fig. 1a), which reveals the successful doping of Na ions into the host matrix. The average crystallite size of Pristine and Na doped CuO were calculated by measuring the full-width at the half-maximum of the most intense diffraction peak (-111) using Debye–scherrer equation, D =0.9λ/ β cosθ, where D is the average crystallite size, λ, the wavelength of the incident X-ray beam (1.540Å), θ, the