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Visible Light Photocatalytic Properties of Modified Titanium Dioxide Nanoparticles via Aluminium Treatment Dessy Ariyanti; Junzhe Dong; Junye Dong; Wei Gao
Bulletin of Chemical Reaction Engineering & Catalysis 2016: BCREC Volume 11 Issue 1 Year 2016 (April 2016)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.11.1.414.40-46

Titanium dioxide (TiO2) has gained much attentions for the last few decades due to its remarkable performance in photocatalysis and some other related properties. However, its wide bandgap (~3.2 eV) can only absorb UV energy which is only ~5% of solar light spectrum. The objective of this research was to improve the photocatalytic activity of TiO2 by improving the optical absorption to the visible light range. Here, colored TiO2 nanoparticles range from light to dark grey were prepared via aluminium treatment at the temperatures ranging from 400 to 600 oC. The modified TiO2 is able to absorb up to 50% of visible light (400-700 nm) and shows a relatively good photocatalytic activity in organic dye (Rhodamine B) degradation under visible light irradiation compared with the commercial TiO2.

A Leak Free Phase Change Materials with Enhanced Thermal Buffering Properties by TiO2/Biochar Ariyanti, Dessy; Huda, Khoirul; Bayu Samudra, Muhammad; Lesdantina, Dina; Adi Saputra, Erwan; Hamzah, Fazlena
Reaktor Volume 23 No.3 December 2023
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.23.3.116-126

A leak free organic phase change material of palmitic acid with enhanced thermal buffering properties was synthesized by simple chemical TiO2/biochar encapsulation process. By utilizing the optimum amount of TiO2 as an encapsulation agent the minimalization of leakage phenomena during the phase change process can be achieved with the value 20-25% of weight loss. Furthermore, the additional sugar cane bagasse-based biochar that was introduced to the encapsulation system acts as a support matrix that enhances further the leakage properties into free leak category with the percentage of weight lost 1.1-1.4 %. Moreover, the introduction of sugar cane bagasse-based biochar in the encapsulation system of the palmitic acid PCM can improve the thermal buffering properties by keeping a package box temperature in the range of 2-80C for more than 20 h by means small increment of temperature 0.72oC/h. Keywords: PCM, encapsulation, palmitic acid, thermal buffering, leakage

Mangrove Conservation and Biodiversity Protection Strategies in Universitas Diponegoro to Achieve Net Zero Emission Ambariyanto, Ambariyanto; Utama, Yos Johan; Sugianto, Denny Nugroho; Ariyanti, Dessy; Handayani, Elinna Putri
Journal of Sustainability Perspectives Vol 3, No 2: December 2023
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jsp.2023.20482

Indonesia is set the net zero emission target to be achieved by 2060. As part of that, Universitas Diponegoro (UNDIP) is committed to support the achievement of the goal by implementing several strategies. First is to reduce the amount of emission generated by the university daily activities, and second is boosting the activities of mangrove conservation and biodiversity protection. As UNDIP located in the northern part of Central Java, part of 108.000 kilometers coastline region of Indonesia, UNDIP prioritizes its academic activity and research focus on coastal region environmental and ecological development which enthuse the implementation of mangrove conservation and biodiversity protection. The strategy includes the structured mangrove and biodiversity conservation action directed by the University leaders, encouraging research and community service activities focusing on coastal region development and developing environmental-related curriculum for the students. In addition, UNDIP also supports research centers and students’ communities who focus on mangrove conservation, biodiversity protection, and coastal region development. By that, there are more than 50 types of flora in UNDIP land forest with carbon stock calculation up to 6,480.20 metric tons CO2 eq. Acc

Mangrove Conservation and Biodiversity Protection Strategies in Universitas Diponegoro to Achieve Net Zero Emission Ambariyanto, Ambariyanto; Utama, Yos Johan; Sugianto, Denny Nugroho; Ariyanti, Dessy; Handayani, Elinna Putri
Journal of Sustainability Perspectives Vol 3, No 2: December 2023
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jsp.2023.20482

Indonesia is set the net zero emission target to be achieved by 2060. As part of that, Universitas Diponegoro (UNDIP) is committed to support the achievement of the goal by implementing several strategies. First is to reduce the amount of emission generated by the university daily activities, and second is boosting the activities of mangrove conservation and biodiversity protection. As UNDIP located in the northern part of Central Java, part of 108.000 kilometers coastline region of Indonesia, UNDIP prioritizes its academic activity and research focus on coastal region environmental and ecological development which enthuse the implementation of mangrove conservation and biodiversity protection. The strategy includes the structured mangrove and biodiversity conservation action directed by the University leaders, encouraging research and community service activities focusing on coastal region development and developing environmental-related curriculum for the students. In addition, UNDIP also supports research centers and students’ communities who focus on mangrove conservation, biodiversity protection, and coastal region development. By that, there are more than 50 types of flora in UNDIP land forest with carbon stock calculation up to 6,480.20 metric tons CO2 eq. Acc

Characteristics of all organic redox flow battery (AORFB) active species TEMPO-methyl viologen at different electrolyte solution Ariyanti, Dessy; Purbasari, Aprilina; Hapsari, Farida Diyah; Saputra, Erwan Adi; Hamzah, Fazlena
International Journal of Renewable Energy Development Vol 13, No 5 (2024): September 2024
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2024.60155

The practice of using wind and solar energy to generate electricity represents a solution that would be beneficial for the environment and ought to be explored. However, in order to ensure users' stability and continuous access to electricity, the increasing usage of renewable energy needs to align with the advancement of energy storage technologies. Redox flow batteries, which use an organic solution as the electrolyte and a proton exchange membrane as an ion exchange layer, are currently the subject of extensive research as one of the alternative renewable energy storage systems with the benefit of a techno economy. This study investigated the solubility of organic solution, namely 2,2,6,6-Tetramethylpiperidinyloxy or 2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO) and methyl viologen (MV) in various essential electrolyte solutions such as NaCl, KCl, KOH, and H2SO4 that can be used as electrolytes of all organic redox flow battery (AORFB) system to produce high energy density and charging and discharging capacity. The result shows the optimum condition for effective charge transfer in AORFB is TEMPO catholyte and MV anolytes in the 0.08 M H2SO4electrolyte solution. Additionally, a correlation between the acquisition of electrolyte solutions on TEMPO catalyst and MV anolytes was discovered by the data. Electrolyte solution can improve electrical conductivity in TEMPO solution, which in turn can improve the efficiency of AORFB charging and discharging. Contrarily, MV anolytes exhibit a different pattern where the addition of electrolyte solutions reduces their electrical conductivity. RFBs systems with the aforementioned catholyte and anolyte can be used to store solar energy with a maximum current of 0.6 A for 35 minutes. Storage effectiveness is characterized by a change in colour in the catholyte and anolyte. The findings firming the possibility of using AORFB as one of the alternative energy storage systems that can accommodate the intermittence of the renewable energy input resource.

Circular Economy Approach for Sustainable Tree Litters Waste Management, study case in Universitas Diponegoro Ariyanti, Dessy; Ambariyanto, Ambariyanto; Utama, Yos Johan; Sugianto, Denny Nugroho; Hapsari, Farida Diyah
Journal of Sustainability Perspectives Vol 4, No 2: December 2024
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jsp.2024.24809

Universitas Diponegoro, with an open forest area and planted vegetation of 30 – 40%, produced vast amounts of organic waste, especially tree litter. Piles of tree litter are everywhere if it is not properly managed. Universitas Diponegoro has taken a comprehensive approach to handling leaf and tree litter by converting it into economically valuable and beneficial products to meet the objectives of SDGs 12, which are focused on Responsible Consumption and Production. Through the Technical Implementation Unit for Occupational Safety, Health, and Environment (UPT K3L) Universitas Diponegoro has pyrolyzed tree branches to create liquid smoke and anaerobically converted leaf waste into compost. Later, the liquid smoke produced by pyrolysis and compost can achieve the consumer demand standard. In addition, from the policy approach, it is mandatory for every building to handle tree litter surrounds into compost using composting pits and composting bags. The circular economy idea has been incorporated into waste management at Universitas Diponegoro.

Circular Economy Approach for Sustainable Tree Litters Waste Management, study case in Universitas Diponegoro Ariyanti, Dessy; Ambariyanto, Ambariyanto; Utama, Yos Johan; Sugianto, Denny Nugroho; Hapsari, Farida Diyah
Journal of Sustainability Perspectives Vol 4, No 2: December 2024
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jsp.2024.24809

Universitas Diponegoro, with an open forest area and planted vegetation of 30 – 40%, produced vast amounts of organic waste, especially tree litter. Piles of tree litter are everywhere if it is not properly managed. Universitas Diponegoro has taken a comprehensive approach to handling leaf and tree litter by converting it into economically valuable and beneficial products to meet the objectives of SDGs 12, which are focused on Responsible Consumption and Production. Through the Technical Implementation Unit for Occupational Safety, Health, and Environment (UPT K3L) Universitas Diponegoro has pyrolyzed tree branches to create liquid smoke and anaerobically converted leaf waste into compost. Later, the liquid smoke produced by pyrolysis and compost can achieve the consumer demand standard. In addition, from the policy approach, it is mandatory for every building to handle tree litter surrounds into compost using composting pits and composting bags. The circular economy idea has been incorporated into waste management at Universitas Diponegoro.

Sedimentation Process of TiO2 Nanoparticles in Aqueous Solution Ariyanti, Dessy; Purbasari, Aprilina; Lesdantina, Dina; Saputro, Erwan Adi; Gao, Wei
Reaktor Volume 22 No.2 August 2022
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.22.2.70-76

TiO2 nanoparticles, a semiconductor photocatalyst is widely used in various applications especially for water treatment. The common problems for the application are separating the nanoparticles from the water body and recovering it to be reused. This research was conducted to investigate the aggregation and sedimentation properties of TiO2 nanoparticles via chemical addition. The experiment was carried out for 5 hours by varying the pH, ionic strength, and the addition of organic matter such as rhodamine B, methylene orange, and humic acid. The results indicate that pH and ionic strength greatly affect the TiO2 sedimentation process. Sedimentation can be formed properly when the solution is at pH 1 and 14, this happens because pH is close to the isoelectric point. Meanwhile, ionic strength with a concentration of 0.1 M gave the most optimal results in TiO2 sedimentation. In the presence of ionic strength with the appropriate concentration, the thickness of the electrical double layer particles can be reduced so the attractive force increases and sedimentation occur. Meanwhile, in the presence of organic matter, rhodamine B, methylene orange, and humic acid did not significantly affect the formation of TiO2 sedimentation.Keywords: titanium dioxide, sedimentation, ionic strength, isoelectric point, water treatment

Biochar supported photocatalyst (mangrove biochar-TiO2) for organic pollutants removal via synergetic adsorption-photocatalytic process Azizah, Nadya Ummi; Ariyanti, Dessy; Lesdantina, Dina; Saputra, Erwan Adi; Srivastava, Vimal Chandra
Communications in Science and Technology Vol 10 No 1 (2025)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.10.1.2025.1619

Access to clean water remains a global challenge, which is made worse by the contamination of chemical dyes. The recent innovations of wastewater treatment have been introduced, such as combined biochar with TiO2 photocatalyst. This study proposed to degrade mainly organic pollutants from dyed wastewater using adsorption-photocatalytic of biochar-supported photocatalyst TiO2 (BSP). Mangroves were converted into biochar via hydrothermal carbonization process and combined with TiO2 by a sol-gel method. The composite was then characterized by SEM-EDX, FTIR, and XRD. The degradation performance of the BSPs was optimized with the addition of Titanium (IV) Isopropoxide (TTIP) solution in biochar for 15-25 mL, solution photocatalyst dosage 0.5–1 g/L, initial dyed water concentration at 10 ppm, pH 5.2, and UV-irradiation time from 30 to 240 min in a photocatalytic reactor. The phenomenon of organic pollutants removal was observed based upon the mechanism and dominance of the process and the degradation reaction rate of organic pollutants in dyed wastewater. Methylene blue used as a model dye was degraded 100% through the adsorption-photocatalysis process using BSP. The highest effective degradation performance was found in BSP 20 that had a functional group area of 4.39923 m²/g, a catalyst loading of 0.5 g/L, and the highest degradation rate at k = 0.021 min?¹. In subsequent development, the synergistic interaction between biochar and TiO2 presents a promising avenue for the development of advanced wastewater treatment systems targeting the removal of organic pollutants, particularly in textile industry.

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