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<p>Graphene-like layered transition metal carbides, nitrides, or carbonitrides, called MXenes, obey the stoichiometric formula of M<InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(_{n+1}\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mrow> <mi>n</mi> <mo>+</mo> <mn>1</mn> </mrow> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>X<InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(_{n}\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mi>n</mi> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>T<InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(_{x}\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mi>x</mi> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>, where M is an early transition metal such as scandium (Sc), <i>n</i> is a natural number, X is C, N, or CN, and T<InlineEquation ID="IEq8"> <EquationSource Format="TEX">\(_{x}\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mi>x</mi> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation> is a functional group such as –O, –F, or –OH that passivates the surface of the MXene. The electronic structure of bare Sc<InlineEquation ID="IEq9"> <EquationSource Format="TEX">\(_2\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>C and functionalized Sc<InlineEquation ID="IEq10"> <EquationSource Format="TEX">\(_2\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>CT<InlineEquation ID="IEq11"> <EquationSource Format="TEX">\(_{x}\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mi>x</mi> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation> MXenes are explored by performing first-principles density functional theory (DFT) calculations. The bare Sc<InlineEquation ID="IEq12"> <EquationSource Format="TEX">\(_2\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>C is metallic, but less stable than its passivated structure. The Sc<InlineEquation ID="IEq13"> <EquationSource Format="TEX">\(_2\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>C MXene has an interlayer 2D electron gas not bound to Sc or C atoms but free to move, making it an electride. DFT calculations show that functionalization can open an energy gap in Sc<InlineEquation ID="IEq14"> <EquationSource Format="TEX">\(_2\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>CT<InlineEquation ID="IEq15"> <EquationSource Format="TEX">\(_{x}\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mi>x</mi> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation> MXenes. The size and type (direct versus indirect) of the bandgap vary with the functional groups, which provides a means for opening and tuning of the band gap.</p>

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Role of Surface Termination in the Structural and Electronic Properties of Sc\(_2\)CT\(_\textrm{x}\) MXene

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2026年3月22日

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  • Da’Shawn M. Morris,
  • Ashna Upreti,
  • Emily W. Sacquety,
  • Jiya Gorintala,
  • Sauryavi Dhakal,
  • Chandra M. Adhikari

摘要

Graphene-like layered transition metal carbides, nitrides, or carbonitrides, called MXenes, obey the stoichiometric formula of M \(_{n+1}\) n + 1 X \(_{n}\) n T \(_{x}\) x , where M is an early transition metal such as scandium (Sc), n is a natural number, X is C, N, or CN, and T \(_{x}\) x is a functional group such as –O, –F, or –OH that passivates the surface of the MXene. The electronic structure of bare Sc \(_2\) 2 C and functionalized Sc \(_2\) 2 CT \(_{x}\) x MXenes are explored by performing first-principles density functional theory (DFT) calculations. The bare Sc \(_2\) 2 C is metallic, but less stable than its passivated structure. The Sc \(_2\) 2 C MXene has an interlayer 2D electron gas not bound to Sc or C atoms but free to move, making it an electride. DFT calculations show that functionalization can open an energy gap in Sc \(_2\) 2 CT \(_{x}\) x MXenes. The size and type (direct versus indirect) of the bandgap vary with the functional groups, which provides a means for opening and tuning of the band gap.