Exposure to short-term cold stress delays flowering by activating the floral repressor FLOWERING LOCUS C (FLC) in Arabidopsis thaliana. The cold signaling attenuator HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE1 (HOS1) negatively regulates cold responses. Notably, HOS1-deficient mutants exhibit early flowering, and FLC expression is suppressed in the mutants. However, it remains unknown how HOS1 regulates FLC expression. Here, we show that HOS1 induces FLC expression by antagonizing the actions of FVE and its interacting partner histone deacetylase 6 (HDA6) under short-term cold stress. HOS1 binds to FLC chromatin in an FVE-dependent manner, and FVE is essential for the HOS1-mediated activation of FLC transcription. HOS1 also interacts with HDA6 and inhibits the binding of HDA6 to FLC chromatin. Intermittent cold treatments induce FLC expression by activating HOS1, which attenuates the activity of HDA6 in silencing FLC chromatin, and the effects of intermittent cold are diminished in hos1 and fve mutants. These observations indicate that HOS1 acts as a chromatin remodeling factor for FLC regulation under short-term cold stress.

To boost the photoelectrochemical water oxidation performance of hematite photoanodes, high temperature annealing has been widely applied to enhance crystallinity, to improve the interface between the hematite-substrate interface, and to introduce tin-dopants from the substrate. However, when using additional dopants, the interaction between the unintentional tin and intentional dopant is poorly understood. Here, using germanium, we investigate how tin diffusion affects overall photoelectrochemical performance in germanium:tin co-doped systems. After revealing that germanium is a better dopant than tin, we develop a facile germanium-doping method which suppresses tin diffusion from the fluorine doped tin oxide substrate, significantly improving hematite performance. The NiFeOx@Ge-PH photoanode shows a photocurrent density of 4.6 mA cm−2 at 1.23 VRHE with a low turn-on voltage. After combining with a perovskite solar cell, our tandem system achieves 4.8% solar-to-hydrogen conversion efficiency (3.9 mA cm−2 in NiFeOx@Ge-PH/perovskite solar water splitting system). Our work provides important insights on a promising diagnostic tool for future co-doping system design.

A semicrystalline p-type thermoelectric conjugated polymer based on a polymer backbone of cyclopentadithiophene and benzothiadiazole, poly­[(4,4′-(bis­(hexyldecyl­sulfanyl)­methylene)­cyclopenta­[2,1-b:3,4-b′]­dithiophene)-alt-(benzo­[c]­[1,2,5]­thiadiazole)] (PCPDTSBT), is designed and synthesized by replacing normal alkyl side-chains with bis­(alkylsulfanyl)­methylene substituents. The sp2-hybridized olefinic bis­(alkylsulfanyl)­methylene side-chains and the sulfur–sulfur (S–S) chalcogen interactions extend a chain planarity with strong interchain packing, which is confirmed by density functional calculations and morphological studies, i.e., grazing incidence X-ray scattering measurement. The doping, electrical, morphological, and thermoelectric characteristics of PCPDTSBT are investigated by comparison with those of poly­[(4,4′-bis­(2-ethylhexyl)­cyclopenta­[2,1-b:3,4-b′]­dithiophene)-alt-(benzo­[c]­[1,2,5]­thiadiazole)] (PCPDTBT) with ethylhexyl side-chains. Upon doping with a Lewis acid, B­(C6F5)3, the maximum electrical conductivity (7.47 S cm–1) of PCPDTSBT is ∼1 order higher than that (0.65 S cm–1) of PCPDTBT, and the best power factor is measured to be 7.73 μW m–1 K–2 for PCPDTSBT with doping 9 mol % of B­(C6F5)3. The Seebeck coefficient–electrical conductivity relation is analyzed by using a charge transport model for polymers, suggesting that the doped PCPDTSBT film has superb charge transport property based on a high crystallinity with olefinic side-chains. This study emphasizes the importance of side-chain engineering by using the sp2-hybridized olefinic substituents to modulate interchain packing, crystalline morphology, and the resulting electrical properties.

We report an efficient Ti-doped FeOOH (Ti-FeOOH) co-catalyst applied on SiOx thin layer coated Ti-doped porous Fe2O3 (Ti-PH) to realize an excellent water splitting photoelectrochemical cell.

Thermoelectric (TE) energy conversion in conjugated polymers is considered a promising approach for low‐energy harvesting and self‐powered temperature sensing. To enhance the TE performance, it is necessary to understand the relationship between the Seebeck coefficient (α) and electrical conductivity (σ). Typical doped polymers exhibit α–σ relationship that is distinct from that of inorganic materials due to their large structural and energetic disorder, which prevents them from achieving the maximum TE power factor (PF = α2σ). Here, an ideal α–σ relationship in the Kang–Snyder model following a transport parameter s = 1 is demonstrated with two degenerately doped semi‐crystalline polymers, poly[(4,4′‐(bis(hexyldecylsulfanyl)methylene)cyclopenta[2,1‐b:3,4‐b′]dithiophene)‐alt‐(benzo[c][1,2,5]thiadiazole)] (PCPDTSBT) and poly[(2,5‐bis(2‐hexyldecyloxy)phenylene)‐alt‐(5,6‐difluoro‐4,7‐di(thiophen‐2‐yl)benzo[c][1,2,5]thiadiazole)] (PPDT2FBT) using a sequential doping method. The results allow the realization of the PFs reaching theoretic maxima (i.e., 112.01 µW m−1 K−2 for PPDT2FBT and 49.80 µW m−1 K−2 for PCPDTSBT) and close to metallic behavior in heavily doped films. Additionally, it is shown that the PF maxima appear when the doping state switches from non‐degenerate to degenerate. Strategies towards an optimal α–σ relationship enable optimization of the PF and provide an understanding of the charge transport of doped polymers.