Fluorescent Carbon Quantum Dots (FCQDs), a new generation of carbon nanomaterials, have attracted a lot of attention throughout the years. This paper applied a straightforward and environmentally beneficial way to create water-soluble FCQDs hydrothermally from coconut shells. The as-prepared FCQDs have desirable functional groups and exhibit strong blue-emitting fluorescence with a relative quantum yield of 0.6 and 0.7%. The optical bandgap of FCQDs is calculated using UV–Vis spectra to be between 3.9 and 4.4 eV. Optical studies show that FCQDs have good fluorescence properties when excited at 360 nm. Whereas the fluorescence decay lifetime using TCSPC are 1.6–0.99 ns. The synthesized FCQDs were found by HRTEM to have a spherical shape and a particle-size distribution of 2.8–5.4 nm. As-prepared FCQDs has a very low hemotoxicity of 0.5 to 1.3%, which indicates that they have acceptable biocompatibility and are not hazardous. According to the DPPH antioxidant data, FCQDs had a stronger antioxidant activity compared to earlier reports. These important characteristics enable its applications in biomedical, food packaging, fluorescence imaging, photocatalysis, and sensing. The enhanced antioxidant characteristics of the produced FCQDs make them appropriate for use in biomedical, bioimaging, chemical, and industrial applications. The as-synthesized FCQDs were used for the detection of ferric ions with good selectivity.

This study involved the heterogenization of a binder pitch (BP) using a small amount of nanocarbon to improve physical properties of the resulting graphite electrode (GE). Heterogenization was carried out by adding 0.5–2.0 wt.% platelet carbon nanofiber (PCNF) or carbon black (CB) to a commercial BP. To evaluate the physical properties of the BPs, we designed a new model graphite electrode (MGE) using needle coke as a filler. The heterogenized binder pitch (HBP) with PCNF or CB clearly increased the coking value by 5–13 wt.% compared to that of the as-received BP. Especially, the model graphite electrodes prepared with HBPs containing 1.0 wt.% PCNF or CB showed significantly improved physical properties compared to the control MGE from the as-received BP. Although the model graphite electrodes prepared with HBPs showed similar properties, they had smaller pore sizes than the control. This indicates that heterogenization of the BP can effectively decrease the pore size in the MGE matrix. Correlating the average pore sizes with the physical properties of the model graphite electrodes showed that, for the same porosity, matrices formed by the HBP with a smaller average pore size can effectively improve the apparent density, tensile strength, and oxidation resistance of the model graphite electrodes.

Activated carbon has broad application prospects for treating pollutants due to its easy availability, low cost and good adsorption. In our work, nano-activated carbons (NAC) with abundant functional groups are obtained by the oxidation modification of HNO3, ( NH4)2S2O8, and KMnO4, which are used to construct the particle electrodes to degrade NDEA in a continuous flow electrochemical reactor, and the influence of relevant factors on the performance of NDEA removal is discussed. The experimental data show that the optimal degradation efficiency is 42.55% at the conditions of 3 mL/min influent water flow, 0.21 M electrolyte concentration, 10 mA/cm2 current density, and 10 μg/mL initial NDEA concentration. The degradation of NDEA conforms to a quasi second order kinetic equation. The electrocatalytic mechanism of NAC electrodes for removing NDEA is firstly discussed. The effects of different free radicals on the degradation of NDEA are also demonstrated through free radical quenching experiments, indicating that the degradation of NDEA is dominated by ⋅OH. The degradation pathway of NDEA and final products are obtained using GC–MS. NAC particle electrodes as the cheap and efficient electrocatalyst in continuous flow electrochemical reactor system provide a greener solution for the removal of disinfection by-products from drinking water.

Drought is one of the environmental factors inhibiting plant productivity and growth, leading to oxidative damage. This study aims to identify the role of sodium hydrosulfide (NaHS) as a hydrogen sulfide (H2S) donor in drought stress tolerance in Brassica napus. Drought-induced stress symptoms appeared eight days after treatment, showing wilted leaves and a significant reduction of leaf water potential. Drought-induced increase of lipid peroxidation was significantly reduced by NaHS application. NaHS-treated plants mitigated stress symptoms under drought conditions by reducing hydrogen peroxide (H2O2) content, confirmed with H2O2 localization in situ. Furthermore, NaHS promotes photosynthetic activity by maintaining chlorophyll and carotenoid content, thereby supporting plant growth under drought conditions. Pyrroline-5-carboxylate and proline contents were significantly increased by drought but further enhanced by NaHS treatment, indicating the important roles of proline accumulation in drought stress tolerance. In conclusion, this study provides valuable insight into the roles of NaHS in alleviating drought stress by reducing oxidative stress and promoting proline accumulation. Therefore, NaHS may serve as an effective strategy to enhance crop production under drought-stress conditions.

This study investigates the role of the NAC transcription factor ANAC032 in regulating abscisic acid (ABA)-dependent stress responses and its involvement in sugar signaling pathways. Arabidopsis seedlings with overexpressed or knock-out ANAC032 were examined for their sensitivity to ABA, glucose, and fluridone to elucidate the functional role of ANAC032 in ABA and high glucose-mediated growth retardation. Our results showed that ANAC032 negatively regulates ABA responses, as ANAC-overexpressing plants exhibited higher ABA sensitivity, while anac032 mutants were less sensitive. Under high glucose conditions, anac032 mutants demonstrated hyposensitivity, with germination rates higher than wild-type and ANAC032-overexpressing plants. Additionally, yeast two-hybrid screening identified three NAC proteins, ANAC020, ANAC064, and ANAC074, interact with ANAC032. These findings highlight ANAC032’s role in stress signaling pathways and its potential interactions with other NAC proteins, contributing to a better understanding of transcriptional regulation in plant stress responses and possibly expanding to forage crop development.

Background: Because oxidative stress can induce decreased quality of caprine semen during the storage, there has been limitation for the use of stored semen in the assisted reproductive technologies. The present study, therefore, assesses the potential of Annona muricata (A. muricata ) to reduce semen storage associateddamages. Methods: Semen was collected by electro-ejaculation from ten bucks, and extended with Tris-egg yolk (TEY) supplemented with A. muricata leaf aqueous extract (SAE) at 20 (SAE20), 40 (SAE40), and 80 (SAE80) μg/mL. Sperm variables including motility, motion characteristics, viability, membrane functionality, and DNA integrity were assessed at different storage periods (6, 24, 48, and 72 hr). In addition, oxidative stress indicators in the extender supplemted with SAE were also assessed for each group. Results: By adding SAE at 80 μg/mL in TEY, the storage of goat buck semen was improved, resulting in reduced loss of sperm motility, viability, DNA fragmentation, and membrane integrity during chilled storage at 4℃ for up to 72 hr. In addition, enrichment of TEY extender with SAE significantly (p < 0.05) reduced malondialdehyde, an indicator of oxidative stress, compared to the negative control. Conclusions: Supplementation of SAE in TEY extender can reduce buck spermatozoa liquid storage associated damages due to oxidative stress.

호접란은 세계적으로 분화뿐만 아니라 절화로도 판매되는 주 요 화훼작물이다. 상업적 종묘 대량생산은 조직배양 기술에 의 해 이루어지고 있으나 우리나라는 아직까지 균일하고 우수한 발근묘 생산 기술이 확립되지 않았다. 생육이 고르고 우수한 발근 배양묘를 생산하기 위한 적정 배양 신초수를 찾기 위해 용적 500mL 유리 배양병에 호접란 2품종(‘Lovely Angel’과 ‘UniVivace’)의 신초를 1, 4, 7, 10개씩 배양한 후 3개월에 지상부 및 지하부 초기 생육 특성을 조사한 결과, 7개의 신초를 배양하였을 때 신초의 생육이나 뿌리 유도 및 생육에 효과적이 었다. 또한, 배양병 재질이 발근묘 생육에 미치는 영향을 확인하 고자 용적이 500mL로 동일한 유리 배양병과 플라스틱 배양병 에 신초 7개 배양 3개월 후 2품종의 생육 특성을 비교한 결과, 2품종 모두 플라스틱 배양병 보다는 유리 배양병이 유의적으로 생육에 효과적인 것으로 확인되었다. 기내 발근묘 생산을 위한 배양병 재질의 영향은 이후까지 지속적으로 영향을 미치는 것으 로 확인되었다. 결론적으로, 균일한 호접란 발근묘 생산은 플라 스틱 재질보다는 유리병 재질의 배양병이 적합하며, 특히, 용적 이 500mL인 유리 배양병의 경우 신초를 7개(묘당 재식면적 5.4㎠) 이내로 배양하는 것이 바람직한 것으로 확인되었다.

목적: 가상현실을 구현하는 HMD의 광학계를 이용하여 가상현실 기반의 사위검사법을 개발하였다. 방법: HMD(Oculus rifts, Oculus, USA)를 이용하여 가상현실에 3m 및 40 cm의 사위 시표를 생성했을 때 HMD의 디스플레이에 송출된 타깃의 분리도를 측정하였고, 광학렌즈에 의해 결상된 디스플레이의 타깃 상 위치와 분리도, 배율 등을 산출하였다. 가상현실의 사위 시표는 수정된 토링톤 시표와 마독스 봉을 기반으로 제작했으며, 가상의 검사실을 제작하였고, 사위 측정 방법을 컨트롤러에 프로그래밍하였다. 결과: 가상현실에 3m 및 40 cm의 사위 시표를 생성했을 때 HMD의 디스플레이에 송출된 타깃의 분리도는 각 각 62.49mm, 58.29mm이었다. 디스플레이의 타깃은 광학렌즈에 의해 상 배율 8.07×로 광학렌즈로부터 전방 269.44mm에 상이 맺었으며, 타깃 상의 분리도는 각각 57.51mm, 20.16mm이었다. 사위 시표의 위치 인식은 HMD 사용자의 양안으로부터 양쪽 디스플레이의 타깃 상을 연결한 양안의 주시선이 교차하는 지점에서 이루어지는 것으로 나타났다. HMD를 착용했을 때 양쪽 디스플레이에 검사실 및 사위 시표가 생성되어 양안이 동시 주시를 하 였고, 컨트롤러의 트리거를 당겼을 때 우측 디스플레이의 영상이 적색선으로 교체되면서 양안의 시선이 분리되었 다. 사위검사 시 검사거리의 전환은 컨트롤러의 y-버튼을 이용했으며, 수평 사위 측정은 우측 컨트롤러의 트리거, 수직 사위 측정은 왼쪽 컨트롤러의 트리거를 이용하였다. 결론: 이상으로 가상현실을 기반의 사위검사법을 개발한 본 연구는 안경광학 분야에서 VR 기술의 활용에 대한 기초자료를 제시하였다고 생각한다.

본 연구는 작약의 품종간 개화시기 차이와 저온에서 장기 저 장이 가능한 품종을 선발하여 절화 유통 기간을 연장하기 위하 여 수행하였다. 작약 24품종을 대상으로 2022년 국립원예특작 과학원 시험포장에서 개화시기와 절화 품질을 조사하였다. 봉오 리 상태에서 수확한 작약을 건조 저장법으로 -1℃에서 60일 저장한 후 절화 수명과 절화품질을 조사하였다. ‘의성작약’은 홑 꽃이었고 나머지 품종은 겹꽃이었다. 개화시기는 5월 10일부터 18일 사이였으며, ‘Etched Salmon’, ‘Monsieur Jules Elie’, ‘Gilbert’, ‘Henry Bockstoce’는 개화일이 5월 10일로 가장 빨랐고, ‘Elsa Sass’는 5월 18일로 가장 늦었다. 식물체 키는 74.6∼107.8cm 였고, 절화 무게는 ‘Henry Bockstoce’ 품종 이 89.8g으로 가장 무거웠고, ‘Angel Cheeks’ 품종이 26.7g으 로 가장 가벼웠다. 꽃의 주된 색은 흰색, 빨강색, 분홍색, 자주색 이었다. -1℃에서 60일간 저장 후에 꽃과 잎의 상태가 아주 양 호한 품종은 ‘Kansas’, ‘Ole Faithful’, ‘Sonw Mountain’이 었다. 절화수명은 ‘Nick Shaylor’ 품종이 8일로 가장 길었고, 다음으로 ‘Blush Queen’, ‘Elsa Sass’ 품종이 7일이었으며, ‘Gilbert’, ‘Highlight’ 품종이 1일로 가장 짧았다. 작약은 저온 장기 저장에서 일부 품종을 제외하고는 꽃과 잎에 저온장해 증 상이 발생하였다. 이와같은 결과는 작약재배시에 품종 선택과 수확후 저온 장기 저장을 통하여 유통기간을 연장하고 하고자 할 때 기초자료로 활용될 수 있을 것으로 기대된다.

This study explores the integration of ChatGPT, OpenAI’s conversational AI, into English as a Foreign Language (EFL) classrooms at Korean universities, focusing on student interactions and language learning strategy preferences. It categorises interactions using the Strategy Inventory for Language Learning (SILL) and Strategic Self-Regulation (S2R) frameworks to evaluate the pedagogical effectiveness of AIassisted learning. Ninety-nine university students participated in training sessions with ChatGPT prompts tailored to different learning strategies. Data were collected through surveys, chat transcripts, and qualitative feedback. Results indicate frequent student interactions with ChatGPT, averaging 4.49 strategies in initial training chats. Compensatory strategies like error correction and adaptive difficulty received high ratings, while social strategies were rated lowest. Metacognitive strategies, especially planning and summarising, were also well-received. The study concludes that ChatGPT supports diverse learning strategies, enhancing linguistic competence and promoting self-regulated learning. However, limitations such as AI accuracy and authenticity issues highlight the need for continued human interaction in language education.

최근 국내외 화장품과 식품산업에서 다양하게 사용되어 지고 있는 콜라겐 단백질 제품은 점차 그 용도와 특성에 따라 보다 고도화, 기능화 되어 가고 있다. 피부 건강의 지표인 콜라겐은 다양한 용도로 개발되어 사용되고 있으 며, 콜라겐의 소비가 증가함에 따라 용도에 적합한 최적 화된 콜라겐 제품의 개발이 중요한 연구 분야이다. 특히 여러 기업과 연구기관들에 의해서 콜라겐의 흡수율을 높 이기 위한 다양한 노력이 이루어지고 있다. 따라서 본 연 구에서는 프란즈(Franz) 세포 시스템을 이용하여 국내에서 판매되는 다양한 분자량별 콜라겐 제품의 경피 및 구강 상피세포 투과성을 비교하였다. 그 결과, 피부 표피/진피 조직과 비교하여 구강점막 조직의 콜라겐 흡수율이 분자 량 500달톤과 1,000달톤의 경우 모두 통계적으로 유의하 게(각각 약 10배, 2배) 높은 것으로 확인되었다. 또한, 분 자량별 구강점막 조직 흡수율을 비교한 결과, 분자량 500 달톤의 콜라겐이 분자량 1,000달톤 제품에 비해 흡수율이 2-3배 증가함을 확인하였다. 분자량 500달톤의 경우 Cmax 와 AUCt 값이 가장 높게 나타났으며, 피부 표피/진피 세 포에 비해 구강점막세포 시험군의 모든 지표가 높은 것으 로 나타났다. 본 연구 결과는 피부 흡수보다는 구강 점막 세포를 통한 콜라겐의 흡수방법이 콜라겐 체내 흡수증가 에 유효한 수단임을 시사하며, 분자량 1,000달톤 이하에서 도 보다 더 작은 500달톤의 저분자 콜라겐의 흡수율이 증 가되는 것으로 보아 콜라겐의 분자량이 흡수율 증가의 주 요한 요소임을 확인할 수 있었다.

We presented foundational findings regarding the occurrence and acoustic characteristics of the finless porpoise through passive acoustic and visual surveys conducted on the southern coast of Korea, specifically at Hadong Jungpyeong Port. Over a survey period spanning from July 8 to August 16, 2023, totaling 40 days, we observed peaks in the number of clicks produced by this species on July 15, July 24, August 4, August 11, and August 16. The highest count, totaling 18,924 clicks, was recorded on July 15th, while the lowest count, at 3,888 clicks, occurred on August 8th. Examining the acoustic characteristics throughout the diurnal cycle, we found that the peak activity in terms of DPM (detection positive minute for one hour), DP10M (DPM for ten minutes), and overall number of click sounds was observed between 05:00 and 08:00, with a secondary peak occurring from 17:00 to 18:00. The quietest period was noted between 23:00 and 02:00. Furthermore, there was a significant increase in the number of clicks from sunrise, with the maximum count of 21,581 clicks recorded at 6 AM. This count gradually decreased until noon, experienced a slight increase thereafter, peaked again at sunset, and then declined. The dominant frequency mode of this species was 126 kHz, with a concentration ranging from 112 to 136 kHz. The average duration of a click sound was 127 ㎲, with approximately 16 sinusoids (cycles) within each click sound and an average cycle length of approximately 7.9 ㎲. These findings from our study are anticipated to serve as foundational data for the development of a Korean pinger and acoustic warning system.

대부분의 사람들은 시궁창에 있지만, 니심 이지키엘처럼 그들 중 일부는 별을 바라본다. 그가 태어난 날부터 죽을 때까지, 그는 평범한 사람들이 가지고 있지 않은 특별한 무언가를 가지고 있었다. 그는 태어나지 않은 노래의 샘을 “휘젓는” 능력을 가지고 있었고, 그의 심장에 불이 붙은 바람을 느꼈다. 시인과 평범한 사람의 차이는 단어 사용에 숨겨져 있다. 이지키엘은 재치 있는 조각가와 같았다. 그는 자신의 시의 특정 줄에 적합한 단어와 구절을 선택하는 데 익숙했다. 만약 그가 원래 초안에 만족하지 못한다면, 그는 최종 작품이 오늘날에도 그 안에서 볼 수 있는 위엄으로 빛날 때까지 계속해서 썼다. 그는 모호함에 대해 반란의 깃발을 올렸다. 그는 표현이 명확하고 단순한 어법으로 이루어져야 한다는 것을 알고 있었다. 그 외에도 이지키엘에게 시는 단순한 시집이 아니라 그보다 더 위대한 것이다. 이 뛰어난 시인의 시적 신조가 발전하는 과정은 순탄하지 않았다. 그것은 물결처럼 출렁였다.

아일랜드의 민족주의자이자 작가인 윌리엄 버틀러 예이츠(1865-1939)의 문학적 재능에는 여러 측면이 있다. 아일랜드 신화와 민속을 영국 식민지주의에 대한 저항으로 활용하고, 1916년 부활절 봉기와 같은 아일랜드 민족주의 투쟁의 긴 역사에서 일어난 사건을 찬양하고, 철학적 묵상, 선견지명적 순간, 상징주의, 낭만주의 등 그는 다양한 문학 장르에서 이 모든 것을 다루었다. 예이츠의 시가 그의 문학 작품에서 가장 중요한 자리를 차지하고 있다는 것은 부인할 수 없다. 예이츠의 성격의 여러 측면 중에서 아일랜드 혁명가 모드 곤의 연인으로 묘사된 예이츠는 잘 알려져 있다. 그녀와 그의 삶에 들어온 다른 여성들에게 영감을 받아 그는 상당수의 연애시를 썼다. 이 논문의 목적은 예이츠의 선택된 연애시에서 여성에 대한 표현을 분석하여 남성의 여성에 대한 태도와 다양한 사랑의 뉘앙스에 대한 그들의 경험에 빛을 비추는 것이다. 이는 아일랜드와 세계 다른 지역의 여성 운동에서 일어난 사건으로 인해 여성의 지위가 변화했다는 점을 감안할 때 중요하다. 이 논문은 세기의 전환기에 공공 영역에서 활동하는 “새로운 여성”이 등장했음에도 불구하고 예이츠의 연애시를 포함한 연애시는 궁정 연애의 전통을 이어가며 사랑하는 사람의 아름다움과 수동성을 찬양한다고 주장한다. 이 논문은 페미니즘 이론의 통찰력을 이용하여 시를 분석한다.

Today, the principles of green chemistry are being fundamentally applied in the chemical industry, such as the nitrobenzene industry, which is an essential intermediate for various commercial products. Research on the application of response surface methodology (RSM) to optimize nitrobenzene synthesis was conducted using a sulfated silica (SO4/SiO2) catalyst and batch microwave reactor. The nitrobenzene synthesis process was carried out according to RSM using a central composite design (CCD) design for three independent variables, consisting of sulfuric acid concentration on the silica (%), stirring time (min), and reaction temperature (°C), and the response variable of nitrobenzene yield (%). The results showed that a three-factorial design using the response surface method could determine the optimum conditions for obtaining nitrobenzene products in a batch microwave reactor. The optimum condition for a nitrobenzene yield of 63.38 % can be obtained at a sulfuric acid concentration on the silica of 91.20 %, stirring time of 140.45 min, and reaction temperature of 58.14 °C. From the 20 experiments conducted, the SO4/SiO2 catalyst showed a selectivity of 100 %, which means that this solid acid catalyst can potentially work well in converting benzene to nitrobenzene.

Copper, silver, and gold-reduced graphene oxide nanocomposite (Cu-rGO, Ag-rGO, and Au-rGO) were fabricated via the hydrothermal method, which shows unique physiochemical properties. Environment friendly electromagnetic radiation was employed to synthesize rGO from GO. The nonlinear optical phenomenon of noble metal decorated rGO is predominantly due to excited state absorption, which arises from surface plasmon resonance and increases in defects at the surface due to Cu, Ag, and Au incorporation. It is found that the third-order nonlinear absorption coefficient was in the order of 10− 10 m/W, with notable enhancements in the third-order properties of Au-rGO compared to other nanocomposites and their respective counterparts. Functionalizing rGO induces defect states ( sp3), increasing NLO response. Cu, Ag, and Au exhibit higher Surface-Enhanced Raman Scattering (SERS) activity due to rGO-induced structural modifications. SERS signals are influenced by dominant signals from Au nanorods. The electronic structures for pure and doped rGO were investigated through Density Functional Theory (DFT). The computed partial density of states (PDOS) confirms the enhancement of the state in Au-doped rGO is due to the charge transference from Au to C 2p orbital. The optical absorption spectra and PDOS reveal the possibility of free carrier absorption enhancement in Au which validates experimentally observed higher two-photon absorption (β) value of Au-doped rGO. The tuning of nonlinear optical and SERS behaviour with variation in the noble metal upon rGO provides an easy way to attain tuneable properties which are exceedingly required in both optoelectronics and photonics applications.

Electrochemical water splitting presents an optimal approach for generating hydrogen ( H2), a highly promising alternative energy source. Nevertheless, the slow kinetics of the electrochemical oxygen evolution reaction (OER) and the exorbitant cost, limited availability, and susceptibility to oxidation of noble metal-based electrocatalysts have compelled scientists to investigate cost-effective and efficient electrocatalysts. Bimetallic nanostructured materials have been demonstrated to exhibit improved catalytic performances for the oxygen evolution reaction (OER). Herein, we report carbon aerogel (CA) decorated with different molar ratios of Fe and Ni with enhanced OER activity. Microwave irradiation was involved as a novel strategy during the synthesis process. Inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope (SEM), Energy dispersive X-ray spectroscopy (EDAX spectra and EDAX mapping), Transmission Electron Microscope (TEM), High-Resolution Transmission Electron Microscope (HR-TEM), and Selected Area Electron Diffraction (SAED) were used for physical characterizations of as-prepared material. Electrochemical potential towards OER was examined through cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS). The FeNi/CA with optimized molar ratios exhibits low overpotential 377 mV at 10 mAcm− 2, smaller Tafel slope (94.5 mV dec− 1), and high turnover frequency (1.09 s− 1 at 300 mV). Other electrocatalytic parameters were also calculated and compared with previously reported OER catalysts. Additionally, chronoamperometric studies confirmed excellent electrochemical stability, as the OER activity shows minimal change even after a stability test lasting 3600 s. Moreover, the bimetallic (Fe and Ni) carbon aerogel exhibits faster catalytic kinetics and higher conductivity than the monometallic (Fe), which was observed through EIS investigation. This research opens up possibilities for utilizing bi- or multi-metallic anchored carbon aerogel with high conductivities and exceptional electrocatalytic performances in electrochemical energy conversion.

Energy storage is one of the leading problems being faced globally, due to the population explosion in recent times. The conventional energy sources that are available are on the verge of extinction, hence researchers are keen on developing a storage system that will face the upcoming energy needs. Supercapacitors, also known as ultracapacitors or electrochemical capacitors, are advanced energy storage devices characterised by high power density and rapid charge–discharge cycles. Unlike traditional batteries, supercapacitors store energy through electrostatic separation, offering quick energy release and prolonged operational life. They hold exceptional performance in various applications, from portable electronics to electric vehicles, where their ability to deliver bursts of energy efficiently complements or replaces conventional energy storage solutions. Ongoing research focuses on enhancing energy density and overall efficiency, positioning supercapacitors as pivotal components in the evolving landscape of energy storage technologies. A novel electrode material of NiO/CuO/Co3O4/rGO was synthesized which when used as a supercapacitor, the highest value of CS is 873.14 F/g which is achieved for a current density of 1 A/g under with an energy density of 190 Wh/kg and the highest power density of 2.5 kW/kg along with 87.3% retention after 5000 GCD cycles under 1 M KOH.

Flexible electrodes, particularly paper electrodes modified with polypyrrole, have shown promise in energy-related applications. We have earlier demonstrated the usage of paper electrodes modified with polypyrrole as a flexible and suitable photoanode for photoelectrochemical water splitting (PEC). Further, modification of this electrode system with an appropriate tandem absorber system for solar fuel production is interesting in developing efficient photoanodes. In this study, we study the PEC performance of flexible polypyrrole-based paper photoanodes (PPy-PAs) by decorating them with rGO@Cu2Zn- SnS4 chalcopyrites (rGO@CZTS/PPy-PAs). The lower bandgap (~ 1.5 eV) of the rGO@CZTS/PPy-PAs system allows for efficient visible light absorption, substantially improving PEC water-splitting reactions. The rGO@CZTS/PPy-PAs exhibited an enhanced current density of ~ 13.2 mA/cm2 at 1.23 V vs RHE, ABPE of ~ 1.5%, and a hydrogen evolution rate of 177 μmoles/min/cm2. Overall, rGO@CZTS/PPy-PAs showed 2.1-fold, 1.1-fold, and 1.4-fold enhancement in photocurrent activity over PPy-PAs, CZTS/PPy-PAs, and rGO/PPy-PAs, respectively. The usability of rGO@CZTS/PPy-PAs is established in the form of stable photocurrent for more than 200 min. These findings open new possibilities for developing modified PPy PAs as flexible PEs for efficient solar-driven PEC devices and give directions on improving flexible PEs for flexible and efficient solar-driven PEC systems.