Karakteristik Sensor Gas Hidrogen dari Bahan Semikonduktor TiO2 (Titanium Dioxide) Didoping Na2CO3 (Natrium Carbonat)

Telah dilakukan karakterisasi sensor gas hidrogen berupa pelet dari bahan semikonduktor TiO2-Na2CO3. Pelet sensor gas hidrogen dibuat sebanyak enam sampel dengan variasi komposisi yang berbeda. Tahap pembuatan sensor gas hidrogen terdiri atas pencampuran bahan, kalsinasi pada temperatur 500 oC selama 4 jam, penggerusan, kompaksi, dan sintering pada temperatur 700 oC selama 4 jam. Sensor gas hidrogen diuji pada temperatur ruang dengan melihat karakteristik I-V, nilai sensitivitas, nilai konduktivitas, waktu respon, dan karakterisasi XRD. Berdasarkan pengukuran karakteristik I-V, sampel dengan variasi mol  98% mol TiO2 + 2% mol Na2CO3 merupakan sampel dengan hasil terbaik karena memiliki nilai sensitivitas tertinggi. Sensitivitas yang didapat yaitu 3,18 pada tegangan 6 volt. Nilai konduktivitas tertinggi dimiliki sampel 98% mol TiO2 + 2% mol Na2CO3 yaitu 1,30 x 10-3/Ωm pada lingkungan hidrogen. Waktu respon sampel 98% mol TiO2 + 2% mol Na2CO3 pada tegangan 6 volt adalah 57 sekon. Hasil XRD menunjukkaan ukuran kristal 98% mol TiO2 + 2% mol Na2CO3 lebih besar dibandingkan dengan TiO2 murni.Kata kunci: sensor gas hidrogen, TiO2-Na2CO3, sensitivitas, konduktivitas, waktu respo

Karakterisasi I-V Semikonduktor CuO Didoping TiO2 sebagai Sensor Gas Hidrogen

Telah dilakukan karakterisasi sensor gas hidrogen berupa pelet dengan bahan utama CuO yang didoping dengan TiO2. Pelet sensor gas hidrogen dibuat dengan variasi doping TiO2 0%, 2%, 4%, 6%, 8% dan 10% terhadap bahan utama CuO. Sensor gas hidrogen dibuat dengan metode reaksi keadaan padat. Sensor gas hidrogen diuji pada temperatur ruang dengan melihat karakteristik I-V, sensitivitas, konduktivitas, waktu respon, dan kristalinitas. Karakteristik I-V menunjukkan bahwa sampel dengan doping TiO2 sebanyak 6% mol memiliki sensitivitas tertinggi yaitu 2,80 pada tegangan operasional 9 Volt. Nilai konduktivitas tertinggi dimiliki sampel CuO doping 6% mol TiO2 yaitu 19,65 x 10-5/Ωm pada lingkungan hidrogen. Waktu respon, konduktivitas dan ukuran kristal dari sampel yang memiliki sensitivitas tertinggi akan diukur. Waktu respon sampel CuO didoping 6% mol TiO2 adalah 42 s pada tegangan 9 Volt. Hasil XRD menunjukkan ukuran kristal CuO didoping 6% mol TiO2 yaitu 143,40 nm lebih besar dibandingkan dengan bahan CuO tanpa doping yaitu 128,21. Sensor gas hidrogen telah mampu membedakan kondisi di lingkungan hidrogen dengan kondisi di lingkungan udara, dengan sensitivitas yang tinggi dan waktu respon yang singkat. Sensor yang paling optimal digunakan adalahCuO didoping 6% mol TiO2. Kata kunci : sensor gas hidrogen, CuO, TiO2, sensitivitas, konduktivitas, waktu respo

Ni-doped TiO2 nanotubes for wide-range hydrogen sensing

Doping of titania nanotubes is one of the efficient way to obtain improved physical and chemical properties. Through electrochemical anodization and annealing treatment, Ni-doped TiO(2) nanotube arrays were fabricated and their hydrogen sensing performance was investigated. The nanotube sensor demonstrated a good sensitivity for wide-range detection of both dilute and high-concentration hydrogen atmospheres ranging from 50 ppm to 2% H(2). A temperature-dependent sensing from 25°C to 200°C was also found. Based on the experimental measurements and first-principles calculations, the electronic structure and hydrogen sensing properties of the Ni-doped TiO(2) with an anatase structure were also investigated. It reveals that Ni substitution of the Ti sites could induce significant inversion of the conductivity type and effective reduction of the bandgap of anatase oxide. The calculations also reveal that the resistance change for Ni-doped anatase TiO(2) with/without hydrogen absorption was closely related to the bandgap especially the Ni-induced impurity level

Optical and Electrochemical Properties of Self-Organized TiO2 Nanotube Arrays From Anodized Ti−6Al−4V Alloy

Due to their high specific surface area and advanced properties, TiO2 nanotubes (TiO2 NTs) have a great significance for production and storage of energy. In this paper, TiO2 NTs were synthesized from anodization of Ti-6Al-4V alloy at 60 V for 3 h in fluoride ethylene glycol electrolyte by varying the water content and further annealing treatment. The morphological, structural, optical and electrochemical performances of TiO2 NTs were investigated by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), UV-Visible spectroscopy and electrochemical characterization techniques. By varying the water content in the solution, a honeycomb and porous structure was obtained at low water content and the presence of (α + β) phase in Ti-6Al-4V alloy caused not uniform etching. With an additional increase in water content, a nanotubular structure is formed in the (α + β) phases with different morphological parameters. The anatase TiO2 NTs synthesized with 20 wt% H2O shows an improvement in absorption band that extends into the visible region due the presence of vanadium oxide in the structure and the effective band gap energy (Eg) value of 2.25 eV. The TiO2 NTs electrode also shows a good cycling performance, delivering a reversible capacity of 82 mAh.g−1 (34 μAh.cm−2.μm−1) at 1C rate over 50 cycles

Recent Advancements in TiO2 Nanostructures: Sustainable Synthesis and Gas Sensing

The search for sustainable technology-driven advancements in material synthesis is a new norm, which ensures a low impact on the environment, production cost, and workers' health. In this context, non-toxic, non-hazardous, and low-cost materials and their synthesis methods are integrated to compete with existing physical and chemical methods. From this perspective, titanium oxide (TiO2) is one of the fascinating materials because of its non-toxicity, biocompatibility, and potential of growing by sustainable methods. Accordingly, TiO2 is extensively used in gas-sensing devices. Yet, many TiO2 nanostructures are still synthesized with a lack of mindfulness of environmental impact and sustainable methods, which results in a serious burden on practical commercialization. This review provides a general outline of the advantages and disadvantages of conventional and sustainable methods of TiO2 preparation. Additionally, a detailed discussion on sustainable growth methods for green synthesis is included. Furthermore, gas-sensing applications and approaches to improve the key functionality of sensors, including response time, recovery time, repeatability, and stability, are discussed in detail in the latter parts of the review. At the end, a concluding discussion is included to provide guidelines for the selection of sustainable synthesis methods and techniques to improve the gas-sensing properties of TiO2

Hydrogen Sensing with Ni-Doped TiO2 Nanotubes

Doping with other elements is one of the efficient ways to modify the physical and chemical properties of TiO2 nanomaterials. In the present work, Ni-doped TiO2 nanotubes were fabricated through anodic oxidation of NiTi alloy and further annealing treatment. The hydrogen sensing properties of the nanotube sensor were investigated. It was found that the Ni-doped TiO2 nanotubes were sensitive to an atmosphere of 1,000 ppm hydrogen, showing a good response at both room temperature and elevated temperatures. A First-Principle simulation revealed that, in comparison with pure anatase TiO2 oxide, Ni doping in the TiO2 oxide could result in a decreased bandgap. When the oxide sensor adsorbed a certain amount of hydrogen the bandgap increased and the acceptor impurity levels was generated, which resulted in a change of the sensor resistance