Studi Komputasi Pengaruh Doping Ni terhadap Struktur Elektronik dan Adsorpsi H2O pada Permukaan TiO2

Lestari, Nurfitri Ayu (2026) Studi Komputasi Pengaruh Doping Ni terhadap Struktur Elektronik dan Adsorpsi H2O pada Permukaan TiO2. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Penelitian ini bertujuan untuk menganalisis pengaruh doping nikel (Ni) terhadap sifat elektronik titanium dioksida (TiO₂) serta interaksinya dengan molekul H₂O melalui pendekatan Density Functional Theory (DFT) dengan metode hybrid Generalized Gradient Approximation (GGA) dan fungsi pertukaran-korelasi PBE0. Sifat elektronik dianalisis melalui Frontier Molecular Orbital (FMO) dan Density of States (DOS), sedangkan mekanisme interaksi dengan molekul H₂O diamati dari termodinamika adsorpsi dan transfer muatan. Hasil analisis menunjukkan bahwa doping Ni menyebabkan distorsi lokal dan pembentukan mid-gap states yang secara signifikan memodifikasi struktur elektronik sistem. Konfigurasi singlet menghasilkan penurunan celah pita (Eg) yang signifikan hingga ~1,65–1,97 eV, disertai peningkatan afinitas elektron dan karakter elektrofilik yang mendukung proses transfer muatan. Temuan ini diperkuat oleh analisis DOS yang mengonfirmasi kemunculan orbital 3d-Ni di sekitar level Fermi, sehingga meningkatkan densitas keadaan elektronik dan memungkinkan eksitasi elektron dengan energi lebih rendah (cahaya tampak). Adsorpsi H₂O berlangsung secara disosiatif pada situs Ti dan secara molekular pada situs Ni, dengan energi adsorpsi relatif kuat dan berlangsung menguntungkan secara termodinamika. Selain itu, analisis transfer muatan mengindikasikan mekanisme donor–akseptor yang menghasilkan heterogenitas situs aktif. Sistem Ti₁₃O₂₈Ni-13 menunjukkan stabilitas dan performa adsorpsi paling optimal. Secara keseluruhan, doping Ni efektif dalam merekayasa struktur elektronik TiO₂ dan meningkatkan kinerja adsorpsi serta potensi fotokatalitiknya.
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This study aims to analyze the effect of nickel (Ni) doping on the electronic properties of titanium dioxide (TiO₂) and its interaction with H₂O molecules using a Density Functional Theory (DFT) approach with the hybrid Generalized Gradient Approximation (GGA) method and the PBE0 exchange–correlation functional. The electronic properties were analyzed through Frontier Molecular Orbital (FMO) and Density of States (DOS), while the interaction mechanism with H₂O molecules was examined based on adsorption thermodynamics and charge transfer. The results show that Ni doping induces local structural distortion and the formation of mid-gap states, which significantly modify the electronic structure of the system. The singlet configuration results in a substantial reduction of the band gap (Eg) to approximately 1.65–1.97 eV, accompanied by an increase in electron affinity and electrophilic character that facilitates charge transfer processes. These findings are further supported by DOS analysis, which confirms the emergence of Ni 3d orbitals near the Fermi level, thereby increasing the electronic state density and enabling electron excitation at lower energy (visible light region). H₂O adsorption occurs dissociatively at Ti sites and molecularly at Ni sites, with relatively strong adsorption energies that are thermodynamically favorable. In addition, charge transfer analysis indicates a donor–acceptor mechanism that generates heterogeneity in active sites. The Ti₁₃O₂₈Ni system shows the most optimal stability and adsorption performance. Overall, Ni doping is effective in engineering the electronic structure of TiO₂ and enhancing its adsorption performance and photocatalytic potential.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Adsorpsi, Density of States, Struktur Elektronik, TiO₂, Transfer Muatan Adsorption, Charge Transfer, Density of States, Electronic Structure, TiO₂
Subjects:	Q Science > QD Chemistry Q Science > QD Chemistry > QD716 Photocatalysis.
Divisions:	Faculty of Mathematics and Science > Chemistry > 47201-(S1) Undergraduate Thesis
Depositing User:	Nurfitri Ayu Lestari
Date Deposited:	01 Aug 2026 04:17
Last Modified:	01 Aug 2026 04:17
URI:	http://repository.its.ac.id/id/eprint/141355

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