This work focuses on the synthesizing of g-C3N4/CuO nanocomposites by thermal decomposition and their nonlinear optical characterization. The XRD pattern shows that the crystalline peaks of copper oxide increase with the increase in concentration of copper acetate hydrate. The existence of vibrational modes was studied using FTIR. The vibrational peak at 812 cm−1 is due to the triazine ring and the Cu–O stretching vibration is represented by the peak at about 529 cm−1. With the increase in concentration, there is a red shift in the curves due to the effective interaction between g-C3N4 and CuO. The nanostructures were confirmed using FESEM. Raman spectroscopy confirms the Ag and 2Bg phonon modes of CuO. The G mode around 1586 cm−1 and the D mode around 1350 cm−1 is due to g-C3N4. The nonlinear optical properties, including the nonlinear coefficient of absorption (β), nonlinear coefficient of refraction (n2) and third-order nonlinear susceptibility <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_14439_Article_IEq1.gif" Format="GIF" Height="20" Rendition="HTML" Resolution="72" Type="Linedraw" Width="31" /> </InlineMediaObject> <EquationSource Format="TEX">$(\chi^{3} )$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <msup> <mi>χ</mi> <mn>3</mn> </msup> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation> were investigated using the Z-scan technique at a wavelength of ~ 532 nm. The Nonlinear coefficient of absorption was found to be increase from <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_14439_Article_IEq2.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="82" /> </InlineMediaObject> <EquationSource Format="TEX">$1.35\times {10}^{-4}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>1.35</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>-</mo> <mn>4</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation> to <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_14439_Article_IEq3.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="82" /> </InlineMediaObject> <EquationSource Format="TEX">$1.18\times {10}^{-5}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>1.18</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>-</mo> <mn>5</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation> cm/W and negative nonlinear refraction due to self-defocusing varies from <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_14439_Article_IEq4.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="90" /> </InlineMediaObject> <EquationSource Format="TEX">$2.019\times {10}^{-9}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>2.019</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>-</mo> <mn>9</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation> cm2/W to <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_14439_Article_IEq5.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="90" /> </InlineMediaObject> <EquationSource Format="TEX">$0.897\times {10}^{-9}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>0.897</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>-</mo> <mn>9</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation> cm2/W. The estimated value of third-order susceptibility is found to be increased from <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_14439_Article_IEq6.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="82" /> </InlineMediaObject> <EquationSource Format="TEX">$2.71\times {10}^{-7}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>2.71</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>-</mo> <mn>7</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation> to <InlineEquation ID="IEq7"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_14439_Article_IEq7.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="82" /> </InlineMediaObject> <EquationSource Format="TEX">$1.23\times {10}^{-6}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>1.23</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>-</mo> <mn>6</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation> e.s.u., respectively. The limiting threshold was decreased from 5.07 to 0.074 kJ/cm2 with the increase in wt% of CuO. The low value of limiting threshold, makes them promising optoelectronic materials for optical sensors.

Study of nonlinear properties of g-C3N4/CuO nanocomposites and application as optical limiters

期刊论文
发表日期：

2025年3月6日

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Reetu Sangwan,
Monika Barala,
Neelamma Gummagol,
Kavita Yadav,
Bajinder Singh,
Devendra Mohan,
Parutagouda Shankaragouda Patil

摘要

This work focuses on the synthesizing of g-C₃N₄/CuO nanocomposites by thermal decomposition and their nonlinear optical characterization. The XRD pattern shows that the crystalline peaks of copper oxide increase with the increase in concentration of copper acetate hydrate. The existence of vibrational modes was studied using FTIR. The vibrational peak at 812 cm⁻¹ is due to the triazine ring and the Cu–O stretching vibration is represented by the peak at about 529 cm⁻¹. With the increase in concentration, there is a red shift in the curves due to the effective interaction between g-C₃N₄ and CuO. The nanostructures were confirmed using FESEM. Raman spectroscopy confirms the A_g and 2B_g phonon modes of CuO. The G mode around 1586 cm⁻¹ and the D mode around 1350 cm⁻¹ is due to g-C₃N₄. The nonlinear optical properties, including the nonlinear coefficient of absorption (β), nonlinear coefficient of refraction (n₂) and third-order nonlinear susceptibility $(\chi^{3} )$ $(χ^{3})$ were investigated using the Z-scan technique at a wavelength of ~ 532 nm. The Nonlinear coefficient of absorption was found to be increase from $1.35\times {10}^{-4}$ $1.35 \times 10^{- 4}$ to $1.18\times {10}^{-5}$ $1.18 \times 10^{- 5}$ cm/W and negative nonlinear refraction due to self-defocusing varies from $2.019\times {10}^{-9}$ $2.019 \times 10^{- 9}$ cm²/W to $0.897\times {10}^{-9}$ $0.897 \times 10^{- 9}$ cm²/W. The estimated value of third-order susceptibility is found to be increased from $2.71\times {10}^{-7}$ $2.71 \times 10^{- 7}$ to $1.23\times {10}^{-6}$ $1.23 \times 10^{- 6}$ e.s.u., respectively. The limiting threshold was decreased from 5.07 to 0.074 kJ/cm² with the increase in wt% of CuO. The low value of limiting threshold, makes them promising optoelectronic materials for optical sensors.