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"Among semiconductors, zinc oxide (ZnO) has received great attention due to its wide band-gap and high electron mobility, resulting in various strategic applications. Controlling the physical properties of ZnO is therefore a critical issue in the fabrication of related electronic and optical devices. In this study, ZnO nanorods layers were grown on an ITO glass substrate via chemical bath deposition at low temperature. Prior to the growing process, the layers were deposited using a spin-coating technique. The seeding solution was made by dissolving zinc nitrate tetrahydrate and hexamethylene tetraamine in cold water (0oC) for an hour using a cooler bath. The as-synthesized ZnOs were further subjected to different post-hydrothermal treatment series at a temperature of 150oC for three hours at atmospheric pressure and at 100°C for one hour under one bar of nitrogen gas (N2) pressure. The characterization was performed using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and UV-Vis spectroscopy. The SEM results showed that the ZnO nanorods were grown as a vertically aligned hexagonal structure, while the XRD patterns showed a high intensity at the (002) plane. On the basis of investigation, it was found that under post-hydrothermal treatment at 150oC for three hours with atmospheric pressure, the synthesis procedure resulted in nanostructures in the form of ZnO rods. Meanwhile, post-hydrothermal treatment at 100°C for one hour under one bar of nitrogen gas (N2) produced ZnO rods and tubes. In general, the post-hydrothermal process provided a high degree of crystallinity. The optimum ZnO layer was obtained after post-hydrothermal treatment at 150oC for three hours at atmospheric pressure, with a crystallite size and band-gap energy of ~18 nm and 3.20 eV, respectively."

"Aktifitas fotokatalis nanostruktur ZnO dapat ditingkatkan dengan berbagai cara, termasuk rekayasa struktur elektronika material melalui penambahan atau doping logam transisi. Pada umumnya ZnO doping Co untuk aplikasi fotokatalis disintesis dalam bentuk lapisan tipis atau serbuk, masih sangat sedikit penelitian sintesis nanorod ZnO doping Co yang ditumbuhkan langsung diatas substrat yang lebih praktis dalam aplikasinya. Dalam penelitian ini, nanorod ZnO ditumbuhkan diatas permukaan substrat kaca dengan metode ultrasonic spray pyrolysis dan hidrotermal. Aaktivitas fotokatalitik nanorod ZnO diuji melalui degradasi larutan methylene blue MB dibawah sinar UV. Hasil karakterisasi menggunakan FESEM, EDX, XRD, UV-Vis, DRS, PL, Raman, dan XPS menunjukkan bahwa doping Co dapat meningkatkan laju degradasi MB. Peningkatan laju degradasi akibat dari peningkatan ukuran nanorod, peningkatan absorbansi dan emisi pada daerah UV serta menurunnya band gap sebagai akibat interaksi antara elektron atom Co dengan elektron atom Zn dan O. Nanorod ZnO doping Co 7 memiliki aktivitas fotokatalitik tertinggi yang mampu mendegradasi 79,73 MB dalam waktu 38 menit.

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The photocatalyst activitity of ZnO nanostructure can be enhanced in various ways, including the modification of electronic structure through the addition of transition metals elements. Generally, Co doped ZnO for photocatalyst applications were synthesized in the form of thin films or powders. It is rarely researchs on the synthesis of Co doped ZnO nanorods grown on the substrates that have more practical for photocatalyst application. In this study, ZnO nanorods were grown on the surface of glass substrates by ultrasonic spray pyrolysis and hydrothermal methods. The photocatalytic activity of ZnO nanorods was performed by degradation of methylene blue MB under UV radiation.

The characterization results using FESEM, EDX, XRD, UV Vis, DRS, PL, Raman, and XPS show that Co doping can increase the degradation rates. This improvement may be due to the increase of nanorods size, the increase of UV absorbance and emissions on and decrease of band gap as a result of exchange interactions between electrons of Co with electrons of Zn and O. ZnO nanorods with doping Co 7 mol has the highest photocatalytic activity that is capable to degrade 79,73 MB within 38 minutes."

"Zinc oxide (ZnO) nanorods have been considered as a potential semiconductor oxide material for the application of dye-sensitized solar cells (DSSC). Various experiments have been conducted to improve its nanostructural characteristics and functional properties in order to make it well suited for enhancing DSSC’ performance. Inspired by such studies, the ZnO nanorods array was grown on indium tin oxide (InSn2O3, ITO) substrate in the present work. For this purpose, a seed solution was prepared at low temperature (0oC) using zinc nitrate tetrahydrate and hexamethylenetetramine. The ZnO seed layers were deposited onto ITO glass using a spin-coating technique and further annealed at two different temperatures, 200 and 400 oC. The seeding was also varied between one, three and five layers, prior to the growing process using the chemical bath deposition method (CBD). The results showed that the annealing temperatures significantly influenced the ZnO nanorods’ growth. The optimal condition was achieved by using three seed layers annealed at 200oC, providing an average diameter of 157.58 nm, the biggest crystallite size (up to 59.63 nm), and a band-gap energy (Eg) of 3.27 eV. Based on the obtained properties, the growth of ZnO nanorods on ITO substrate in this work has the potential to be used for the application of dye-sensitized solar cells."

"Zinc Oxide (ZnO) is an important semiconductor material due to its broad applications, such as in the fields of electronics, optoelectronics, photocatalysts, and solar cells. The main purpose of this work was to investigate the effect of pressure in post-hydrothermal treatment on crystallinity enhancement, crystallite growth, and band gap reduction of ZnO nanoparticles, which could be expected to improve their performance as the semiconductor oxide layer in the dye-sensitized solar cell application. For this purpose, ZnO nanoparticles have been successfully synthesized through the precipitation method, followed by a sequence of thermal treatments including drying, calcination, and Post-hydrothermal Treatment (PHT). For increasing the crystallinity of ZnO nanoparticles, PHT was carried out with a pressure variation of 1 and 3 bar. The resulting nanoparticles were further characterized with X-Ray Diffraction (XRD), Ultra-Violet Visible (UV-Vis) spectroscopy and a Scanning Electron Microscope (SEM). The study showed that by increasing the PHT pressure from 1 to 3 bar caused an adverse effect on the crystallinity, i.e. the crystallite size of ZnO nanoparticles slightly decreased from 27.42 to 26.88 nm. This was expected to be due to the increase of the boiling point of water causing less effective of vapor generated to improve the crystallinity by a cleavage mechanism on the inorganic framework. The band gap energy (Eg), however, was found to increase slightly from 3.25 to 3.26 eV, respectively. Considering the obtained properties, ZnO nanoparticles in this study have the potential to be used as the semiconductor oxide layer in the dye-sensitized solar cells."

"ABSTRAKSeng oksida (ZnO) telah diaplikasikan sebagai pemanas transparan. Namun, penelitian tentang mikrorod ZnO sebagai pemanas transparan belum dikembangkan. Pada penelitian ini dilakukan fabrikasi lapisan tipis mikrorod ZnO dengan metode chemical bath deposition. Material yang digunakan yaitu zinc nitrate tetrahydrate dan heksametilentetramine. Varibel pada penelitian ini yaitu konsentrasi larutan bibit sebesar 0.005, 0.010, 0.015, 0.025, dan 0.050 M serta perlakuan hidrotermal pada sampel 0.015 M. Karakterisasi mikrorod ZnO dilakukan dengan menggunakan XRD, FESEM, UV-Vis dan four point probe. Hasil penelitian menunjukkan peningkatan konsentrasi larutan mampu menurunkan celah pita energi, E_g mikrorod ZnO yaitu 3.60 menjadi 3.18 eV dan meningkatkan ukuran kristalit yaitu 41.541 hingga 95.076 nm. Diameter terbesar mikrorod ZnO yaitu 288.252 nm pada konsentrasi 0.015 M. Selain itu, peningkatan konsentrasi larutan menyebabkan transmitansi dan resistivitas turun yaitu masing-masing sebesar 72% menjadi 35% dan 0.787 x10^-4 menjadi 0.013 x 10^-4 Ωcm. Perlakuan hidrotermal pada sampel 0.015 M menyebabkan penurunan diameter dari 288. 252 menjadi 125.824 nm dan meningkatkan ukuran kristalit serta menurunkan E_g yaitu masing-masing 71.198 menjadi 165.696 nm dan 3.25 menjadi 3.19 eV. Selain itu, perlakuan hidrotermal menurunkan transmitansi dan resistivitas  yaitu masing-masing sebesar  50.5% menjadi 38% dan  1.126 x 10^-4 menjadi 0.833 x 10^-4 Ωcm. Perlakuan hidrotermal menghasilkan pemanas transparan yang optimum.

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Zinc oxide (ZnO) has been applied as a transparent heater. However, research on ZnO microrod as transparent heaters has not been developed. In this study, the fabrication of microrod ZnO was carried out by using the chemical bath deposition method. The material used is zinc nitrate tetrahydrate and hexamethylentetramine. The variables in this study were the concentration of seed solutions of 0.005, 0.010, 0.015, 0.025, and 0.050 M and the hydrothermal treatment in the sample 0.015 M. The characterization of ZnO microrod was carried out using XRD, FESEM, UV-Vis and four point probes. The results showed an increase in solution concentration was able to reduce the energy band gap, E_g of ZnO microrod which is 3.60 to 3.18 eV and increase the size of the crystallite which is 41.541 to 95.076 nm. The largest diameter of ZnO microrod is 288.252 nm at a concentration of 0.015 M. In addition, an increase in the concentration of the solution causes transmittance and resistivity to decrease, from 72% to 35% and from 0.787 x10^-4 to 0.013 x 10^-4 Ωcm, respectively. The hydrothermal treatment of 0.015 M sample caused a decrease in diameter from 288. 252 to 125.824 nm and increased the size of the crystallite and lowered Eg, from 71.198 to 165.696 nm and from 3.25 to 3.19 eV, respectively. In addition, it has decreases transmittance and resistivity from 50.5% to 38% and from 1.126 x 10^-4 to 0.833 x 10^-4 Ωcm, respectively. The hydrothermal treatment produces optimum transparent heaters.

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"Seng oksida (ZnO) merupakan material semikonduktor dengan aplikasi yang sangat luas dalam berbagai bidang seperti elektronik, optoelektronik, fotokatalisis, hingga biomedis. Salah satu aplikasi yang marak diteliti saat ini adalah penggunaan ZnO sebagai lapisan anoda untuk sel surya tersensitasi zat pewarna (dye-sensitized solar cell, DSSC). Dalam pembuatan sel surya, kondisi morfologi natural lapisan semikonduktor oksida sangat berpengaruh pada interaksi penyerapan cahaya. Bentuk morfologi yang baik adalah struktur one-dimensional (1D) yang tersusun secara paralel dan melekat secara vertikal pada substrat kaca konduktif. Akan tetapi, struktur ini tidak mudah didapat pada sintesis dengan metode kimiawi basah. Pertumbuhan nanostruktur dengan arah yang tidak terorientasi akan mengakibatkan rendahnya kristalinitas dan energi celah pita (Eg) yang tinggi. Hal ini dapat menyebabkan rendahnya kemampuan penyerapan zat pewarna (dye) yang memberikan hasil DSSC dengan efisiensi rendah. Pada penelitian ini, dilakukan sintesis nanostruktur ZnO di atas substrat kaca konduktif dengan bahan dasar seng nitrat tetrahidrat (Zn(NO3)2.4H2O, Zn-nitrat) dan heksametilentetraamin (C6H12N4, HMTA). Untuk meningkatkan kestabilan lapisan ZnO di atas substrat, dilakukan penempelan lapisan bibit terlebih dahulu dengan menggunakan metode spin-coating. Lapisan bibit ini dibuat dengan menggunakan larutan yang disintesis pada suhu 0oC. Setelah proses spin-coating, lapisan nanostruktur ZnO ditumbuhkan dengan menggunakan metode chemical bath deposition (CBD). Untuk meningkatkan kristalinitas nanostruktur ZnO, dilakukan proses pasca-hidrotermal, yang terbagi menjadi 2 variasi. Pada variasi pertama, reaksi dilakukan dalam reaktor hidrotermal pada 150oC selama 3 jam. Pada variasi kedua, reaksi dilakukan dalam reaktor tertutup dengan penambahan gas nitrogen (N2) 1 bar pada suhu 100oC selama 1 jam. Hasil penelitian menunjukkan bahwa perlakuan pasca-hidrotermal, menhasilkan lapisan nanostruktur ZnO dengan kristalinitas yang lebih tinggi, ditandai dengan intensitas puncak difraksi yang lebih tajam dibandingkan dengan ZnO hasil as-synthesized. Naiknya kristalinitas tersebut selanjutnya memicu penurunan energi celah pita (Eg) sehingga lapisan nanostruktur ZnO dapat menyerap cahaya pada panjang gelombang yang lebih besar. Selain itu, morfologi yang yang terlihat dari hasil SEM juga menunjukkan perbaikan setelah proses pasca-hidrotermal. Hal ini terlihat orientasi nanostruktur ZnO yang semula tidak beraturan menjadi tegak vertikal. Dalam penelitian ini, diketahui bahwa perbedaan kondisi pasca-hidrotermal menghasilkan pertumbuhan nanostruktur dengan bentuk yang berbeda. Pada variasi pertama, didapat hasil sintesis berupa nanorods ZnO, sedangkan variasi kedua menghasilkan nanorods dan nanotubes ZnO. Nanostruktur ZnO di atas substrat kaca konduktif yang telah dihasilkan selanjutnya digunakan sebagai lapisan anoda pada DSSC. Pada penelitian ini, terlihat bahwa perbedaan variasi proses pasca-hidrotermal mempengaruhi kemampuan penyerapan warna (dye loading). Anoda yang dihasilkan dari proses pasca-hidrotermal yang menggunakan penambahan gas N2 mampu menyerap za pewarna lebih banyak. Hal ini diduga disebabkan oleh adanya struktur nanotubes yang memiliki pori/rongga. Namun demikian, efisiensi tertinggi diraih oleh anoda setelah perlakuan pasca-hidrotermal tanpa gas N2, yaitu sebesar 0,12%. Nilai ini bersesuaian dengan ukuran kristalit yang paling stabil dan energi celah pita paling rendah yang didapat dari perhitungan. Pada penelitian, diameter kristalit dan energi celah pita pada sampel dengan efisiensi tertinggi adalah sebesar ~18 nm dan 3,17 eV.

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Zinc oxide (ZnO) is a semiconductor material with a very broad application in many fields, such as electronics, optoelectronic, photocatalyst, and biomedicine. One application that widely examined nowadays is its use as an anode layer for dye-sensitized solar cells (DSSC). In solar cells fabrication, the nature of morphological conditions of the oxide semiconductor layer greatly affect the interaction of light absorption. Good morphology is a one-dimensional structure (1D) arranged in parallel and attached vertically on a conductive glass substrate. However, this structure is not easily obtained in the synthesis via wet chemical method. Nanostructures with non-oriented growth will result in lower crystallinity and higher band gap energy (Eg) is high. This can lead to low dye absorption that results in DSSC with low efficiency.

In this study, synthesis of ZnO nanostructures on a conductive glass substrate was carried out using zinc nitrate tetrahydrate (Zn(NO3)2.4H2O, Zn-nitrate) and heksametilentetraamin (C6H12N4, HMTA) at 0oC. To improve the stability of ZnO layer on the substrate, seeding layers were attached using spin-coating method. After the spin-coating process, the seeding layers were grown using chemical bath deposition (CBD). To improve the crystallinity of nanostructured ZnO, post-hydrothermal process was performed afterward. This process was divided into two variations. In the first variation, the reaction is carried out in a hydrothermal reactor at 150oC for 3 hours. While in the second variation, the reaction is carried out in a closed reactor with the addition of 1 bar nitrogen gas (N2) at 100° C for 1 hour.

The results showed that post-hydrothermal treatment had improved the ZnO nanostructures layer. The diffraction peaks were sharper than the as-synthesized ZnO nanostructure, indicating higher crystallinity. As a consequence, the band gap energy would be lowered. In addition, the morphology also showed improvement in the nanostructures orientation after a post-hydrothermal process. In this research, the difference in the post-hydrothermal conditions generated different shapes of ZnO nanostructures. The first variation resulted ZnO nanorods, while the second variation produced ZnO nanorods and nanotubes.

In this study, it appeared that post-hydrothermal process variations affected the dye loading capacity of the ZnO nanostructure layers. When used as anodes in DSSC, the layer obtained from post-hydrothermal process using N2 gas additions showed a higher dye absorption. The presence of nanotubes structure was assumed to gave this contribution, since this structure had pores / cavities that could absorbed more dyes. However, the highest efficiency achieved by the anode after post-hydrothermal treatment without N2 gas, with the value of 0.12%. This corresponded with the most stable crystallites size and lowest band gap energy obtained from the calculation. In the study, the crystallites size and the band gap energy of this sample were given as ~ 18 nm and 3.17 eV."

"Nanorods ZnO telah menarik minat banyak peneliti karena memiliki karakteristik unik yang berpotensi untuk diaplikasikan pada berbagai divais seperti light-emitting diode (LED), dye-sensitized solar cells (DSSC), dan field-effect transistor. Pengaturan parameter-parameter sintesis untuk mendapatkan karakteristik nanorods ZnO yang sesuai dengan aplikasi-aplikasi strategis tersebut telah dilakukan oleh banyak peneliti. Namun, belum banyak penelitian yang berkaitan dengan karakteristik nanorods ZnO yang sesuai untuk aplikasi pemanasan transparan yang menggabungkan performa panas dan transparansi optik yang tinggi. Oleh karena itu, penelitian ini bertujuan untuk menyelidiki pengaruh variasi waktu pertumbuhan dan temperatur larutan bibit pada sifat optik dan elektrotermal lapisan tipis nanorods ZnO untuk aplikasi pemanas transparan. Untuk keperluan investigasi, larutan bibit disiapkan pada suhu 0, 30, dan 60 ℃ selama 1 jam dengan menggunakan seng nitrat tetrahidrat dan hexamethylenetetramine sebagai prekursor. Lapisan bibit tersebut kemudian diteteskan ke atas substrat kaca ITO dan didiamkan selama 10 menit. Selanjutnya, kaca ITO yang telah ditetesi larutan bibit tersebut diputar menggunakan spin coater dengan kecepatan 2000 rpm selama 20 detik lalu dianil pada temperatur 200℃ selama 5 menit. Setelah proses spin coating, lapisan nanorods ZnO ditumbuhkan menggunakan metode chemical bath deposition (CBD) pada suhu 90 ℃ dengan variasi waktu pertumbuhan yang berbeda (3, 4, dan 5 jam). Sampel yang telah disintesis dikarakterisasi menggunakan X-Ray Diffractometer (XRD), scanning electron microscope (SEM), ultraviolet-visible (UV-Vis) spectrophotometry. Untuk melihat hubungan antara struktur dan morfologi sampel dengan karakterisik optik dan elektrotermalnya, resistivitas listrik diukur menggunakan four-point probe dan performa panas menggunakan termokopel. Hasil penelitian menunjukkan bahwa kinerja pemanas transparan optimal yang menggabungkan transmitansi tinggi dan resistivitas rendah ditemukan dalam sampel yang disiapkan dengan temperatur larutan bibit 30°C dan waktu pertumbuhan 3 jam dengan resistivitas sekitar 0,882×10−4 ohm.cm dan transmitansi sebesar 60,01%. Selain itu, nanorods ZnO dengan waktu pertumbuhan yang lebih lama, kristalinitas yang lebih baik, cakupan substrat yang baik dengan ukuran diameter yang seragam menunjukkan suhu keadaan tunak (steady-state temperature) dan laju pemanasan/pendinginan yang tinggi. Namun, transparansi optiknya menurun secara bertahap dengan pertambahan waktu tumbuh yang diduga sebagai konsekuensi dari peningkatan cakupan nanorods ZnO pada substrat

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ZnO nanorods have been attracting much interest of researchers owing to their unique properties and extensive potential for various applications including light-emitting diode, dye-sensitized solar cells, and field-effect transistor. Controlling synthesis parameters to obtain the desired characteristics of ZnO nanorods for those strategic applications has been done by many investigators. However, there has not been much research related to the suitable characteristics of ZnO nanorods required for a transparent heating application combining high thermal performance and optical transparency. Therefore, this study was aimed at investigating the effect of different growth time and seeds solution temperature on the optical and electrothermal properties of ZnO nanorods thin films. For investigation purposes, the seed solutions were initially prepared at the temperature of 0, 30, and 60℃ for 1 hour by using zinc nitrate tetrahydrate and hexamethylenetetramine as precursors. The ZnO seed layers were subsequently deposited onto ITO glass substrates by spin coating technique before the chemical bath deposition (CBD) growth at temperature of 90℃ for three different growth times (3, 4, and 5 hours). The synthesized ZnO nanorods were characterized by field-emission scanning electron microscopy, x-ray diffraction, and ultraviolet-visible spectrophotometry. To investigate the relationship between the structural and morphological characteristics of the synthesized ZnO nanorods with its electrothermal properties, we measured electrical resistivity using the Four Point Probe and heat performance using thermocouples. The results showed that optimum transparent heater performance combining high transmittance and low resistivity was found in samples prepared with seeds solution temperature of 30°C and growth time of 3 hours with resistivity of 0.882×10−4 ohm.cm and transmittance of 60.01%. In addition, the films for longer growth time with better crystallinity, good substrate coverage, and uniformity in their size exhibited a higher steady-state temperature with higher heating/cooling rate. However, its optical transparency decreased gradually with the prolongation of the growth time, which was expected as a consequence of the increase in ZnO nanorods coverage on the substrates."

"Tesis ini membahas tentang fabrikasi dan pengujian sel surya berbasis sintesa larutan (DSSC) dengan bahan utama ZnO sebagai elektroda dan struktur tandem sebagai struktur utamanya. Bahan ZnO digunakan karena mudah didapatkan dan sifat fisisnya serta energinya memiliki kemiripan dengan bahan bandgap lebar yang sudah lebih dulu digunakan, seperti TiO2, dengan mobilitas elektron yang lebih tinggi. Penulis telah berhasil membuat sampel DSSC berbahan ZnO dengan struktur tandem. Berdasarkan pengujian, tampak bahwa struktur tandem memiliki potensi untuk meningkatkan tegangan keluaran hingga 90%, namun salah satu kendala yang terjadi adalah menjaga kestabilan nilai arus kedua tumpukan DSSC agar nilai arus keluaran struktur tandem tidak mengalami penurunan.

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This tesis describes about fabrication and measurement of DSSC with ZnO as main cathode material and tandem as main structure. ZnO is used because it is easy to be found and its physical and energy characteristics are similar to TiO2 with higher electron mobility. ZnO-based DSSC with tandem structure sample has been made. From the test, it can be seen that tandem structure is able to increase output voltage up to 90%, but one of threat that need to be concerned is the stability of current value for each single DSSC, so that the output current of tandem DSSC won’t be decreased."

"Struktur nano ZnO merupakan salah satu material semikonduktor yang banyak diteliti untuk diaplikasikan dalam devais optoelektronik, fotokatalis dan sensor. Dalam penelitian ini dilakukan proses sintesis nanorod ZnO diatas substrat kaca yang terdiri dari dua tahap yaitu proses pembenihan dengan metode ultrasonic spray pyrolysis dan proses penumbuhan nanorod ZnO dengan metode hidroterma l dengan bantuan gelombang mikro. Fokus penelitian ini adalah mengamati pengaruh konsentrasi bahan penumbuh hexamethyelenentetramine dan zinc nitrate tetrahydrate 0,05 M, 0,1 M dan 0,15 M. Dari hasil SEM, XRD dan UV-Vis menunjukkan bahwa penambahan konsentrasi larutan penumbuh mengakibatka n peningkatan parameter kisi, volume unit sel, ukuran kristalit dari 268 menjadi 426 hingga diameter nanorod dari 89-183 nm menjadi 118-216 nm, serta peningkatan band gap dari 3,20 eV menjadi 3,22 eV. Larutan penumbuh dengan konsentrasi 0,15 M merupakan konsentrasi prekursor terbaik karena dapat menghasilkan absorbansi ultraviolet yang paling tinggi.

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ZnO nanostructure is one of the most studied semiconductor materials for optoelectronic devices, photocatalysts and sensors applications. One way to accelerate the reaction is using microwaves. In this research, ZnO nanorods were grown on glass substrates via seeding process via ultrasonic spray pyrolysis method and growth process via hydrothermal method. The focus of this study is to observe the effect of growth solution concentration of hexamethyelenentetramine and zinc nitrate tetrahydrate 0,05 M, 0,1 M and 0,15 M on the morphology, microstructure and optical properties of ZnO nanorods.

By using Scanning Electron Microscoupe SEM, x ray diffraction XRD and UV VIS spectrometers it is seed that an increase of growth solution concentration resulted in the increases of lattice parameters, unit cell volume, crystallite size of 268 to 426 , and diameter of ZnO nanorods from 89 183 nm to 118 216 nm. And also increase the band gap from 3,20 eV to 3,22 eV. Growth solution with a concentration of 0.15 M is the best precursor concentration as it could produce the highest ultraviolet absorbance."

"ZnO merupakan salah satu semikonduktor yang menarik untuk dikembangkan sebagai fotokatalis untuk mengolah zat pewarna tekstil menjadi produk yang kurang berbahaya. Pada penelitian ini disintesis ZnO nanorod diatas substrat kaca dengan metode Ultrasonic Spray Pyrolysis dan hydrothermal. Untuk meningkatkan aktivitas fotokatalitiknya, nanorod ZnO diberi doping unsur Mn dengan lima konsentrasi yang berbeda 0, 1, 3, 5 dan 7 mol. Hasil karakterisasi dengan menggunakan FESEM, XRD, XPS, Spektroskopi Raman, Spektrofotometer UV-Vis dan Photoluminescence menunjukan bahwa penambahan unsur Mn dapat memperbesar luas permukaan nanorod ZnO, meningkatkan kristalinitas dan cacat kristal khususnya kekosongan O. Hal ini menyebabkan aktifitas fotokatalitiknya dapat meningkat. Penambahan unsur Mn 7 menghasilkan degradasi metil biru tertinggi yaitu 76,75 dalam waktu 38 menit.

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ZnO is one of the interesting semiconductors to be developed as a photocatalyst to process the textile dyes into less harmful products. In this study, ZnO nanorod was synthesized on glass substrate by ultrasonic spray pyrolysis and hydrothermal methods. In order to improve the photocatalytic activity, ZnO nanorods were doped with Mn element with 5 different concentrations 0, 1, 3, 5 and 7 mol.

The characterization results using FESEM, XRD, XPS, Raman Spectroscopy, UV Vis Spectrophotometer and Photoluminescence show that the addition of Mn element can increase the surface area of ZnO nanorod, crystallinity and crystal defect especially vacancy O. This causes the photocatalytic activity was increased. The addition of Mn 7 element resulted in the highest methyl blue degradation of 76.75 within 38 minutes."