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In this study, rGO/CuInS2 has been successfully prepared onto TiO2 thin film using solvothermal method followed by Ag2 S deposition layer by successive ionic layer adsorption and reaction deposition (SILAR) technique. The morphology, structural, and optical properties of TiO2 /rGO/CuInS2 thin film were investigated by using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscope (AFM), X-ray diffraction (XRD) and ultra-violet-visible near infrared spectrophotometer (UV-Vis). For electrical properties, electrochemical impedance spectra (EIS) and current-voltage (I-V) test investigated the interfacial charge-transfer resistances and the conversion efficiency of the samples. Results showed that the average particles size of the samples ranged from ±46.52 to ±53.97 nm in diameter. UV-VIS analysis indicated that TiO2 /rGO/CuInS2 thin film showed better light absorption capability with the presence of Ag2 S deposition layers. The rGO/CuInS2 quantum dot sensitized with Ag2 S layers exhibit a photovoltaic power conversion efficiency of 0.33%, which has great improvement of short circuit current (ISC) comparing with that of rGO/CuInS2 quantum dot sensitized without Ag2 S deposition layers.

The rapid improvements of perovskite solar cells since its inception has been associated the advancements in the perovskite layer itself and the efficiency of the hole transport materials (HTM). As a potential for future energy applications, recording high power conversion efficiency of perovskite solar cells has instigated the search for a more scalable production method with the usage of cheap and nontoxic precursors. By applying the insights from dye-sensitized solar cells fabrications methods, perovskite solar cells possess the ability to improve at a remarkable pace and the potential to be applied directly into the current systems without requiring new arrangements. Deposition of the perovskite layer onto the substrate has been a struggle particularly in the crystallinity, surface defects, toxicity and stability issues. Prerequisite to HTM includes high conductivity, diffusion length and compatibility with neighbouring layers. In this review paper, we will highlight two approaches that able to improve the perovskite solar cells performance namely crystallinity and morphological control of the perovskite and development of hole transporting materials for planar and inverted perovskite solar cells.

In this paper, the synthesis of LaFeO3 based on the gel combustion method has been improved by using citric acid (CA) as a secondary chelating agent on glucose. The synthesized samples were calcined at 600 °C and further characterized using X-ray diffraction (XRD), Fourier transform infrared, field-emission scanning electron microscopy (FESEM), scanning electron microscopy, energy-dispersive X-ray spectrophotometry, N2 adsorption–desorption analyses, thermogravimetric analysis, and UV–vis–near-IR spectroscopy. The XRD data revealed that the pure orthorhombic perovskite phase LaFeO3 was obtained when CA was added on glucose. From FESEM and Brunauer–Emmett–Teller analysis, LaFeO3 synthesized using the addition of CA on glucose potentially showed well-uniform spherical particles and a high specific surface area of 40.77 m2/g with a particle size of 70 nm compared to glucose, which only showed 15.68 m2/g with a particle size of 100–300 nm. The photocatalytic activity of LaFeO3 was evaluated by the degradation...

Perovskite solar cells (PSC) are currently experiencing rapid development due to the potential for achieving high efficiency but the fabrication process is strictly restricted inside an inert environment. This is because high relative humidity (RH) condition may cause irreversible degradation or low quality of perovskite film. Since the film quality and device performance depend strongly on the deposition protocol, a systematic investigation about the impact of one-step and two-step spin coating on perovskite film prepared in high-humidity is needed. Hereby, we developed PSC in humid atmosphere (RH40-50%) using both deposition techniques to find the most easily-adopted coating method for PSC fabrication in high-humidity. Results show that one-step-based sample has numerous pinholes and smaller grain size whereas two-step-based counterpart exhibits compact surface coverage and large grains. Hence, the two-step-based film has higher light absorption, better charge transfer and lower charge recombination. The employment of PCBM as a secondary electron transport layer underneath the perovskite layer in one-step-based sample causes both layers to be washed away by chlorobenzene anti-solvent. However, such undesirable phenomenon is not seen for the two-step-based sample. Therefore, the use of two-step method is strongly recommended for the development of efficient PSC in open atmosphere without humidity restriction.

Perovskite LaFeO3 photocatalyst prepared by using sol-gel glucose method was assembled on graphene oxide sheets to produce integrated photocatalyst-adsorbents (IPCA) and investigated as photocatalyst for the degradation of methylene blue under visible light irradiation. The prepared photocatalyst was characterized by FTIR, XRD, FESEM, BET specific surface area measurement, TEM/HRTEM and UV-Vis spectroscopy analysis. The FTIR, FESEM and TEM analysis has suggested that the photocatalyst LaFeO3 has been successfully embedded at the surface of the graphene oxide (GO) sheets due to a strong interaction between the photocatalyst and the adsorbents matrix. Methylene blue degradation shows that IPCA possesses higher photodegradation kinetics compared to bare LaFeO3 photocatalyst. The resultant photocatalyst also possesses magnetic properties which can overcome the difficulty in recollecting and removal of photocatalyst suspension in water after photocatalytic treatment.

This research involves the rare utilisation of the kapok fibre (Ceiba pentandra) as a raw material for the fabrication of cellulose nanocrystal (CNC) and self-assembled CNC membranes. The isolation of CNC from Ceiba pentandra began with the extraction of cellulose via the chemical alkali extraction by using 5wt% NaOH, followed by the typical acidified bleaching method and, finally, the CNC production through acid hydrolysis with 60wt% H2SO4 at the optimum time of 60min. The prepared CNC was then employed for the preparation of self-assembled membrane through the water suspension casting evaporation technique. The obtained CNC membrane was characterised in terms of its composition, crystallinity, thermal stability, as well as, structural and morphological features with the use of several techniques including FTIR, XRD, AFM, TEM, FESEM, and TGA. The FESEM and AFM analyses had illustrated the achievement of a self-assembled CNC membrane with a smooth surface and a well-distributed nano-porous structure, with the porosity of 52.82±7.79%. In addition, the findings proved that the self-assembled CNC membrane displayed good adsorption capability indicated by the recorded efficiency of 79% and 85% for 10mg/L and 5mg/L of methylene blue in an aqueous solution, respectively.

Regenerated cellulose membrane was used as bio-template nanoreactor for the formation of rutile TiO2 mesoporous, as well as in-situ carbon dopant in acidified sol-gel system. The effects of calcination temperature on the physicochemical characteristic of core-shell nanostructured of bio-templated C-doped mesoporous TiO2 are highlighted in this study. By varying the calcination temperature, the thickness of the carbon shell coating on TiO2, crystallinity, surface area, and optical properties could be tuned as confirmed by HRTEM, nitrogen adsorption/desorption measurement, XRD and UV–vis-NIR spectroscopy. The results suggested that increment in the calcination temperature would lead to the band gap narrowing from 2.95 to 2.80 eV and the thickness of carbon shell increased from 0.40 to 1.20 nm. The x-ray photoelectron spectroscopy showed that the visible light absorption capability was mainly due to the incorporation of carbon dopant at interstitial position in the TiO2 to form OTiC or TiOC bond. In addition, the formation of the carbon core-shell nanostructured was due to carbonaceous layer grafted onto the surface of TiO2 via TiOC and TiOCO bonds. The result indicated that bio-templated C-doped core-shell mesoporous TiO2 prepared at 300 °C exhibited the highest photocatalytic activity. It is worthy to note that, the calcination temperature provided a huge impact towards improving the physicochemical and photocatalytic properties of the prepared bio-templated C-doped core-shell mesoporous TiO2.

Visible light driven C-doped mesoporous TiO2 (C-MTiO2) nanorods have been successfully synthesized through green, low cost, and facile approach by sol-gel bio-templating method using regenerated cellulose membrane (RCM) as nanoreactor. In this study, RCM was also responsible to provide in-situ carbon sources for resultant C-MTiO2 nanorods in acidified sol at low temperatures. The composition, crystallinity, surface area, morphological structure, and optical properties of C-MTiO2 nanorods, respectively, had been characterized using FTIR, XRD, N2 adsorption/desorption, TEM, UV-vis-NIR, and XPS spectroscopy. The results suggested that the growth of C-MTiO2 nanorods was promoted by the strong interaction between the hydroxyl groups of RCMs and titanium ion. Optical and XPS analysis confirmed that carbon presence in TiO2 nanorods were responsible for band-gap narrowing, which improved the visible light absorption capability. Photocatalytic activity measurements exhibited the capability of C-MTiO2 nanorods in degradation of methyl orange in aqueous solution, with 96.6% degradation percentage under visible light irradiation.

The objective of this study was to fabricate dual-layer hollow fiber as a microreactor for potential syngas production via phase inversion-based co-extrusion/cosintering process. As the main challenge of phase inversion is the difficulty to obtain defect-free fiber, this work focuses on the effect of the fabrication parameters, that is, nonsolvent content, sintering temperature and outer-layer extrusion rate, on the macrostructure of the produced hollow fiber. SEM images confirm that the addition of nonsolvent has successfully minimized the finger-like formation. At high sintering temperature, more dense hollow fiber was formed while outer-layer extrusion rate affects the outer layer thickness.

At lower operation temperature of intermediate temperature solid oxide fuel cells (IT-SOFC), polarization resistance was recognized as a limiting step because polarization at cathode is dependent on the rate of oxygen reduction reaction. The enhancement of cathode microstructure is one of the effective ways to improve the reaction rate. Pore former addition method is proven to be able to tailor the microstructure of cathode. The addition of polyether ether ketone (PEEK) as pore former was evaluated and compared with common pore formers (corn starch and graphite) for the microstructure cathode layer. Brush painting technique was used to deposit cathode layer on anode/electrolyte dual layer support hollow fiber. X-ray diffraction (XRD) analysis had proven that the resulting layer was free from impurities after the sintering treatment. Corn starch was able to induced cathode layer with coarse and large interconnected pores for efficient gas diffusion, as was proven by the SEM analysis. Additionally, SEM analysis also showed the formation of fine micropores throughout the layer when graphite was used as the pore former that can provide the increase in triple phase boundary region (TPB) in the layer. PEEK was able to generate both high porosity for oxygen diffusion to the reactive sites and increased number of TPB by the formation of fine microstructure pores in the cathode layer.

The use of recycled newspaper as sustainable cellulose resource for the fabrication of green organic/inorganic hybrid photocatalytic membrane via phase inversion method was highlighted in this study. The incorporation of N-doped TiO2 nanorods as a nanocomposite in regenerated cellulose membrane matrix to great extent has altered its morphological and physicochemical properties, as revealed by FESEM, AFM, FTIR, XRD, XPS, and UV–visible spectroscopy analyses. FTIR analysis suggested that there is a strong interaction between the hydroxyl groups of regenerated cellulose (RC) and the TiO2 nanorods through hydrogen bonding interactions. The UV–visible spectroscopy and XPS analysis confirmed that the highly visible light absorption capability of the prepared RC/TiO2 nanocomposite membrane is due to the existence of nitrogen as dopant in the TiO2 lattice structure. The resultant membranes showed a significant photocatalytic performance in the degradation of phenol in aqueous solution under UV and visible light irradiation, respectively. It was found that 0.5 wt% of TiO2 nanorods was the best loading in the regenerated cellulose membrane (RCM) with desirable physicochemical and photocatalytic properties. This study promotes the use of RC/TiO2 nanocomposite membrane as a new and green portable photocatalyst in the field of wastewater treatment without leaving any photocatalyst in the reaction system. It is crucial to emphasize that the use of a non-toxic solvent-based system in this study provide a significant contribution towards the development of a green technology system.

In this chapter, an overview of the applications of carbon-based polymer nanocomposites for photovoltaic applications is presented. The structures and properties of carbon-based materials are properly introduced. The available methods to prepare carbon-based polymer nanocomposites such as solution mixing, melt blending and melt processing, and in situ polymerization are extensively discussed. In addition, the discussions are also focused on the physical properties of carbon-based polymer nanocomposites. Additionally, the applications of carbon-based polymer nanocomposites in the electrode and active layer of PV devices are also described. The future outlook of carbon-based polymer nanocomposite studies are also discussed to further broaden the perspective of this technology.

In this work, an environmental friendly RC/N-TiO2 nanocomposite thin film was designed as a green portable photocatalyst by utilizing recycled newspaper as sustainable cellulose resource. Investigations on the influence of N-doped TiO2 nanorods incorporation on the structural and morphological properties of RC/N-TiO2 nanocomposite thin film are presented. The resulting nanocomposite thin film was characterized by FESEM, AFM, FTIR, UV-vis-NIR spectroscopy, and XPS analysis. The results suggested that there was a remarkable compatibility between cellulose and N-doped TiO2 nanorods anchored onto the surface of the RC/N-TiO2 nanocomposite thin film. Under UV and visible irradiation, the RC/N-TiO2 nanocomposite thin film showed remarkable photocatalytic activity for the degradation of methylene blue solution with degradation percentage of 96% and 78.8%, respectively. It is crucial to note that the resulting portable photocatalyst produced via an environmental and green technique in its fabrication process has good potential in the field of water and wastewater treatment application.

Solid oxide fuel cells (SOFCs) have been considered as a promising electricity-generation technology because of the relatively high efficiency in the conversion of chemical energy to electrical power. The cathode performance of solid oxide fuel cells (SOFC) depends substantially on its surface area, porosity and microstructure, and therefore the processing method used is very important in determining cathode performance. By optimizing the structural characteristic of the layer, the cathode performance during fuel cell performance can be fully maximized. Polyether ether ketone (PEEK) pore former was introduced in the processing method of cathode layer. The cathode layer was brush painted and sintered at 1200°C for 5 hours. TGA analysis is used to specify the sintering curve for the cathode layer. In addition, three point bending test is used to investigate the change in bending force with the addition of pore former. Characterization via FESEM allows inspection over the induced pore geometry and distribution along the layer. The study can produce a comprehensive structural analysis on the pore former addition in the precursor solution of the cathode layer for SOFC application.

A combination between the nanostructured photocatalyst and cellulose-based materials promotes a new functionality of cellulose towards the development of new bio-hybrid materials for various applications especially in water treatment and renewable energy. The excellent compatibility and association between nanostructured photocatalyst and cellulose-based materials was induced by bio-combability and high hydrophilicity of the cellulose components. The electron rich hydroxyl group of celluloses helps to promote superior interaction with photocatalyst. The formation of bio-hybrid nanostructured are attaining huge interest nowadays due to the synergistic properties of individual cellulose-based material and photocatalyst nanoparticles. Therefore, in this review we introduce some cellulose-based material and discusses its compatibility with nanostructured photocatalyst in terms of physical and chemical properties. In addition, we gather information and evidence on the fabrication techniques of cellulose-based hybrid nanostructured photocatalyst and its recent application in the field of water treatment and renewable energy.

This chapter discusses various methods in characterizing porous ceramic membranes. The fundamental theory and calculation for every approach are given to relate the basic concept of each technique to the results obtained from experiments. A number of techniques are discussed, including gas adsorption/desorption isotherm, permporometry, mercury porosimetry, thermoporometry, bubble point method, and liquid displacement technique. This chapter includes some step-by-step methodologies in obtaining the results of pore properties for ceramic membranes. The view and comparisons that include the advantages and limitations are given in the end of this chapter.

An environmental friendly regenerated cellulose membrane (RCM) was successfully prepared via NaOH/urea aqueous solution system by utilizing recycled newspaper (RNP) as the cellulose source. The morphological and chemical structure of resulting membrane were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, and thermogravimetric analysis (TGA). Results from FTIR and XRD verified that the transparent RCM possesses cellulose II structure. SEM observation revealed that the transparent RCM consist of homogeneous dense symmetric membrane structure and composed of a skin layer with mean roughness parameter Ra, obtained from AFM analysis of 29.53 nm. Pure water flux, water content, water contact angle, porosity, and pore size of the resulting membrane were also measured. This study promotes the potential of the cellulose-based membrane obtained from low cost cellulose source for application in filtration and separation system