Article
Chemistry, Multidisciplinary
Pooja J. Ayare, Noelle Watson, Maizie R. Helton, Matthew J. Warner, Tristan Dilbeck, Kenneth Hanson, Aaron K. Vannucci
Summary: This research demonstrates the photocatalytic synthesis of H2 using a multiphoton mechanism, where both a molecular photocatalyst and a substituted naphthol are excited in the presence of a sacrificial electron donor and proton source. The unique use of a naphthol molecule as both a light absorber and H2 producing catalyst offers a new paradigm for the production of solar fuels in uphill reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Review
Multidisciplinary Sciences
Liuqing Yang, Ce Zhang, Xiwen Yu, Yingfang Yao, Zhaosheng Li, Congping Wu, Wei Yao, Zhigang Zou
Summary: This paper introduces the proposal of Extraterrestrial Artificial Photosynthesis (EAP) technology and its significance in manned space exploration, which converts CO2 into fuel and O-2 in extraterrestrial celestial environments to support deep space exploration by simulating the natural photosynthesis of green plants on Earth. The comparison with existing methods, discussion on material research progress, and future challenges of EAP technology are also explored in depth.
NATIONAL SCIENCE REVIEW
(2021)
Article
Chemistry, Physical
Negah Hashemi, Subhajit Nandy, Keun Hwa Chae, Mohammad Mahdi Najafpour
Summary: This study reports an efficient and stable electrocatalyst, NiFe foam, after undergoing harsh anodization process, for the oxygen-evolution reaction (OER) in water splitting for hydrogen production. The presence of various NiFe (hydr)oxides on the surface of the NiFe foam enhances the OER performance, with a stable NiFe-oxide-based layer protecting the catalyst from further oxidation.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Koteswara Rao Gorantla, Bhabani S. Mallik
Summary: The water dissociation process of graphene hybridized with a cobalt-bipyridine complex was studied through first principles molecular dynamics simulations. Detailed electronic analysis revealed the electronic properties of the catalyst and the variation in the oxidation states of the metal center.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Houssein Nasrallah, Pengbo Lyu, Guillaume Maurin, Mohamad El-Roz
Summary: The RuPy···ReCOPy supramolecular assembly demonstrated high performance in the photocatalytic conversion of CO2 into CO, with a significantly higher turnover frequency and CO quantum yield compared to the benchmark system Ru(bpy)3Cl2 and Re(bpy)(CO)3Cl. Time resolved spectroscopy and Density Functional Theory calculations revealed an electron transfer mechanism contributing to the superior photocatalytic performance of RuPy···ReCOPy.
JOURNAL OF CATALYSIS
(2021)
Review
Chemistry, Inorganic & Nuclear
Qi-Fa Chen, Yu-Hua Guo, Yi-Han Yu, Ming-Tian Zhang
Summary: Water oxidation is a crucial step in producing hydrogen using solar energy in artificial photosynthetic systems. Inspired by the oxygen evolution complex (OEC) in PSII, research has shifted towards non-precious metal catalysts, deepening our understanding of the mechanism of water oxidation.
COORDINATION CHEMISTRY REVIEWS
(2021)
Article
Multidisciplinary Sciences
Linda Zedler, Pascal Wintergerst, Alexander K. Mengele, Carolin Muller, Chunyu Li, Benjamin Dietzek-Ivansic, Sven Rau
Summary: Unequivocal assignment of rate-limiting steps in supramolecular photocatalysts is crucial for optimizing photocatalytic activity. By studying a series of structurally similar photocatalysts, we discovered that the rate at which a two-fold reduced Rh-I species is generated is directly correlated with the observed photocatalytic formation of NADH from NAD(+). Interestingly, the fastest intramolecular electron transfer kinetics for the first electron does not necessarily lead to the fastest photocatalysis.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Oliver Kaestle, Emil Vosmar Denning, Jesper Mork, Andreas Knorr, Alexander Carmele
Summary: This study predicts a mechanism for achieving complete population inversion in semiconductor quantum dots, enabled by non-equilibrium steady states through the interplay of V-type interband transitions and non-Markovian decoherence mechanisms caused by acoustic phonons. The research also demonstrates the application of population inversion for unidirectional excitation transport from one end to the other.
Article
Chemistry, Physical
Mitsuhiko Shizuno, Kosaku Kato, Shunta Nishioka, Tomoki Kanazawa, Daiki Saito, Shunsuke Nozawa, Akira Yamakata, Osamu Ishitani, Kazuhiko Maeda
Summary: Graphitic carbon nitride nanosheets combined with a binuclear Ru(II)-Re(I) complex can selectively reduce CO2 to CO under visible light. The grafting of nanoparticulate rutile TiO2 improves the photocatalytic performance by enhancing charge separation and adsorption. Among different TiO2 polymorphs, anatase exhibits the best forward electron transfer while suppressing back electron transfer.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Kai Huang, Chaoliang Lin, Guangqiang Yu, Peng Du, Xinyu Xie, Xian He, Zhichuan Zheng, Ning Sun, Haolin Tang, Xibo Li, Ming Lei, Hui Wu
Summary: A facile selenium-assisted reduction approach is reported to fabricate Ru/Se-RuO2 composites for acidic oxygen evolution reaction. The synergistic effect of Ru/RuO2 heterostructures and Se doping significantly enhances the electrocatalytic performance.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Cheng Lin, Lianfu Jiang, Dawei Hu, Yiqun Li, Bo Cai, Jing Li, Yu Gu, Luyang Wang, Kan Zhang, Haibo Zeng
Summary: The researchers have developed a novel AsP nanosheets that can serve as a stable electron donor for water reductive hydrogen in the near-infrared region. By coupling with Au nanorods and 1T-MoS2 nanosheets, a ternary heterojunction MoS2-Au-AsP was constructed with optimal H2 production rate.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Plant Sciences
Ido Caspy, Ehud Neumann, Maria Fadeeva, Varda Liveanu, Anton Savitsky, Anna Frank, Yael Levi Kalisman, Yoel Shkolnisky, Omer Murik, Haim Treves, Volker Hartmann, Marc M. Nowaczyk, Wolfgang Schuhmann, Matthias Roegner, Itamar Willner, Aaron Kaplan, Gadi Schuster, Nathan Nelson, Wolfgang Lubitz, Rachel Nechushtai
Summary: To adapt to rapid changes in light conditions in deserts, the green alga Chlorella ohadii undergoes structural and pigment composition changes to minimize photodamage and enhance photosynthesis under extreme high light. The efficiency of PSIHL is higher compared to PSILL, making C. ohadii PSIHL an ideal candidate for designing desert artificial photobiocatalytic systems.
Article
Chemistry, Multidisciplinary
Giuseppina La Ganga, Fausto Puntoriero, Enza Fazio, Mirco Natali, Francesco Nastasi, Antonio Santoro, Maurilio Galletta, Sebastiano Campagna
Summary: The Ru-decorated chitosan fibers and IrO2 subset of NS-RuCh system, prepared by crosslinking, exhibit high quantum yield for photochemical water oxidation.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Multidisciplinary Sciences
Stefano Cestellos-Blanco, Ji Min Kim, Nicholas George Watanabe, Rachel Rebecca Chan, Peidong Yang
Summary: Converting CO2 into value-added products using solar energy is an ideal solution for establishing a closed carbon cycle. By combining microorganisms with light-harvesting nanomaterials into photosynthetic biohybrid systems (PBSs), this goal can be achieved through precise metabolic pathways and harnessing solar light.
Article
Chemistry, Multidisciplinary
Yunxiu Bai, Pengqian Luan, Yunpeng Bai, Richard N. Zare, Jun Ge
Summary: Enzyme-photo-coupled catalysis combines the selectivity of enzymes with the energy input of sunlight to produce fine chemicals. However, large-scale operation faces challenges such as enzyme activity loss and efficient utilization of solar energy. This study presents a large-scale enzyme-photo-coupled catalysis system using gas-sprayed microdroplets, which significantly improves solar energy utilization and enhances enzyme activity for the production of chiral alcohols.
Article
Biophysics
Keisuke Saito, Koji Mitsuhashi, Hiroyuki Tamura, Hiroshi Ishikita
Summary: Based on time-dependent density functional theory and quantum mechanical/molecular mechanics approach, we evaluated the excitation energy transfer (EET) coupling (J) between chlorophylls (Chls) and pheophytins (Pheos) in the protein environment of photosystem II. The results showed that the EET coupling between Chls PD1 and PD2 in the reaction center is weaker than the couplings between PD1 and the accessory ChlD1, and between PD2 and ChlD2, suggesting that PD1 and PD2 are monomeric Chls rather than a special pair. Strongly coupled Chl pairs were found in the CP47 and CP43 core antennas. Chls ligated to specific histidine residues play a role in mediating the EET from the lumenal to stromal layers.
BIOPHYSICAL JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Sho Koyasu, Shoichiro Horita, Keisuke Saito, Minoru Kobayashi, Hiroshi Ishikita, Christalle C. T. Chow, Gouki Kambe, Shigeto Nishikawa, Toshi Menju, Akiyo Morinibu, Yasushi Okochi, Yoshiaki Tabuchi, Yasuhito Onodera, Norihiko Takeda, Hiroshi Date, Gregg L. Semenza, Ester M. Hammond, Hiroshi Harada
Summary: p53 deficiency triggers the activation of HIF-1 and ZBTB2 plays a crucial role in this process. ZBTB2 promotes invasion and growth of p53-deficient cancers and is associated with poor prognosis in lung cancer patients. ZBTB2 N-terminus-mimetic polypeptides inhibit ZBTB2 activity and suppress tumor aggressiveness.
Article
Chemistry, Physical
Masaki Tsujimura, Keisuke Saito, Minaka Sugano, Hiroshi Ishikita
Summary: Diatoms use blue-green light due to the presence of chlorophyll c (Chlc), fucoxanthin, and chlorophyll a/c-binding protein (FCP). The absorption wavelength of Chlc changes upon protonation of the acrylate group, making it a candidate component for photoprotection in diatoms. The absorption wavelength of protonated Chlc is longer than that of deprotonated Chlc, indicating a red shift in the absorption wavelength under high-light conditions.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Hiroyuki Tamura, Keisuke Saito, Shunya Nishio, Hiroshi Ishikita
Summary: Using a combined quantum mechanical/molecular mechanical/polarizable continuum model approach, we investigated the electronic coupling in the electron-transfer process from the oxygen-evolving Mn4CaO5 cluster to the electron acceptor D1-Tyr161 (TyrZ). Our results showed that the electron transfer occurs from Mn3(III) to TyrZ via Mn4(III) in the S0 to S1 transition, and the formation of the open-cubane S2 conformation with Mn4(IV) is favored over the closed-cubane S2 conformation with Mn1(IV) in the S1 to S2 transition. Additionally, D1-Asp170 was found to play a crucial role as a dominant electron-transfer route.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Manoj Mandal, Keisuke Saito, Hiroshi Ishikita
Summary: The replacement of Ca2+ with other alkaline earth metals in photosystem II (PSII) leads to structural changes in the H-bond network and the catalytic cluster, affecting O2 evolution.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Biochemistry & Molecular Biology
Yu Sugo, Hiroshi Ishikita
Summary: In photosynthetic reaction centers from purple bacteria (PbRCs), the reduction of the terminal electron acceptor QB is followed by protonation via specific amino acid residues, such as Asp-L213 and Ser-L223 in Rhodobacter sphaeroides. However, in PbRCs from Thermochromatium tepidum and Blastochloris viridis, Asp L213 is replaced with Asn-L222 and Asn-L213, respectively. This study used quantum mechanical/molecular mechanical calculations to investigate the proton transfer along the asparagine-involved hydrogen bond network. The results suggest that Asn-L222 plays a crucial role in facilitating protonation of QB center dot- in a Grotthuss-like mechanism.
Article
Biochemistry & Molecular Biology
Tomoki Kanda, Hiroshi Ishikita
Summary: Using the crystal structure of HbRC, the redox potential (E-m) values in the electron-transfer branches were calculated by considering the protonation states of all titratable sites. The E-m(A(-1)) for bacteriochlorophyll g in HbRC is lower than E-m(A(-1)) for chlorophyll a in PSI. In contrast, the E-m(F-X) for the Fe4S4 cluster in HbRC is significantly higher than in GsbRC and PSI. It is likely that type I reaction centers have evolved to adapt to their light environments while maintaining electron-transfer cascades.
Article
Chemistry, Physical
Tomoki Kanda, Hiroshi Ishikita
Summary: The electron transfer pathways in type I photosynthetic reaction centers are terminated by two Fe4S4 clusters, F-A and F-B. Protein structures play a crucial role in the electrostatic interaction between the protein environment and Fe4S4 clusters and facilitate electron transfer. We calculated the redox potential values for F-A and F-B in different reaction center structures and found that the F-A-to-F-B electron transfer is energetically downhill in cyanobacterial PSI, isoenergetic in plant PSI, and slightly downhill in GsbRC. The binding of the membrane-extrinsic subunit at the reaction center plays a key role in tuning the redox potentials.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Plant Sciences
Keisuke Saito, Shu Nakao, Hiroshi Ishikita
Summary: The Mn4CaO5 cluster in photosystem II forms hydrogen bonds with D1-His337 and a water molecule. The hydrogen bond distances differ between the two monomer units and can be attributed to protonation and overreduction states.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Biochemistry & Molecular Biology
Yoshihiro Chiba, Masaki Tsujimura, Keisuke Saito, Hiroshi Ishikita
Summary: This article investigates how the acetate molecule is stabilized at the counterion Glu107 moiety in a low-pH environment using molecular dynamics simulations and quantum mechanical/molecular mechanical calculations. The results show that the protonation state of acetate determines its hydrogen bonding with deprotonated Glu107. Additionally, the red-shift of the absorption wavelength at low pH is attributed to the protonation of His23/His80. MD simulations reveal that acetate is released from Glu107 via Asn101 and Arg91 when ionized, explaining its binding and release under different pH conditions.
Article
Biophysics
Masaki Tsujimura, Keisuke Saito, Hiroshi Ishikita
Summary: The experimentally measured stretching vibrational frequencies of O-D and C=O Hbond donor groups can provide valuable information about the H-bonds in proteins. The relationship between these vibrational frequencies and the difference in pKa values between H-bond donor and acceptor groups in bacteriorhodopsin and photoactive yellow protein environments was investigated using a quantum mechanical/molecular mechanical approach. The results show that the vibrational frequencies are correlated with the pKa values, and the shifts in the frequencies are caused by changes in pKa values.
BIOPHYSICAL JOURNAL
(2023)
Article
Multidisciplinary Sciences
Keisuke Saito, Shunya Nishio, Mizue Asada, Hiroyuki Mino, Hiroshi Ishikita
Summary: In photosystem II (PSII), the one-electron oxidation of the Mn4CaO5 cluster leads to the formation of two distinct states, the open-cubane S-2 conformation with low spin and the closed-cubane S-2 conformation with high spin. By calculating exchange couplings in the protein environment and simulating pulsed electron-electron double resonance, the protonation state of the open-cubane S-2 conformation was determined to have a deprotonated water molecule, resulting in the observed g = 2 multiline signal in electron paramagnetic resonance.
Article
Chemistry, Physical
Tomoyasu Noji, Hiroyuki Tamura, Hiroshi Ishikita, Keisuke Saito
Summary: This study investigates the energetics of charge-separated and biradical states in the PixD BLUF domain using a quantum mechanical/molecular mechanical/polarizable continuum model approach. The results show that charge separation is more stable and faster in the W91(out) conformation, leading to the formation of a signaling state through hydrogen bonding and side chain rearrangement. In contrast, the W91(in) conformation exhibits less stability in charge separation and cannot proceed to the signaling state.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)