Single crystalline orthorhombic phase tungsten trioxide monohydrate (O-WO 3 •H 2 O, space group: Pmnb) nanoplates with a clear morphology and uniform size distribution have been synthesized by the hydrothermal method and fabricated on the surface of fluorine doped tin oxide (FTO) coated glass substrates with selective exposure of the crystal facet by the finger rubbing method. The rubbing method can easily arrange the O-WO 3 •H 2 O nanoplates along the (020) facet on the FTO substrate. The O-WO 3 •H 2 O nanoplate can be converted to monoclinic phase WO 3 (γ-WO 3 , space group: P21/n) with dominant crystal facet of (002) without destroying the plate structure. Crystal morphologies, structures, and components of the powders and films have been determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman, X-ray photoelectron spectroscopy, etc. The band gap energies of the O-WO 3 •H 2 O and γ-WO 3 nanoplates were determined as ca. 2.26 and 2.49 eV, respectively. Photoelectrochemical properties of the films with (002) dominant crystal facet have also been checked for discussion of further application in water oxidation. The advantage of (002) facet dominant film was investigated by comparing to one spin-coated γ-WO 3 thin film with the same thickness via photoelectrochemical characterizations such as photocurrent, incident photon to current efficiency, and electrochemical impedance spectroscopy.

In the past decade, flexible electronics have attracted significant research attention due to their distinct features and emerging applications in numerous fields such as, flexible displays, implantable sensors, and energy storage systems, among other applications. Due to the development of flexible electronics, this paper details the substrates employed to produce flexible electronic devices, given that substrates generally govern the overall device properties. The increase in research attention can be attributed to the use of films as flexible substrates, which enable the implementation of numerous design strategies and engineering methodologies, thus leading to extensive advances in the manufacturing quality and prospect of flexible electronics in various applications. This paper provides a comprehensive review of the significance of substrates in flexible wearable electronics over the past decade, such as, the substrate properties requirements, processing classification, important flexible devices, and applications, including sensing, energy storage, and other electronic devices.

HIGHLIGHT This journal isThe photocatalysis, chromism, and sensing capabilities of nanostructured tungsten oxides, such as tungsten trioxide (WO 3 ), its suboxides (WO x , 0

has been dominated by various singlejunction solar cells with a practical efficiency of up to 22%. To date, photovoltaic devices with high efficiency, long lifetime, compact size, and low cost as a highlighter key still require more attention. Current commercially available solar panels based on mono-crystalline silicon (c-Si) wafers for single-junction solar cells dominate the current PV market. So far, laboratory solar cells have been fabricated with an efficiency of nearly 26.3%. Even though the energy conversion efficiency reaches a maximum value of ≈33.5% for the upper theoretical energy conversion efficiency with a bandgap of 1.15 eV. [2,3] Since Russell Shoemaker Ohl's experiment over 80 years ago, the p-n junction has become an important part of modern electronics and optoelectronics. [4] This device is constructed by connecting two types of dopants, n-type and p-type, together. [5,6] As a result, an intrinsic electric field is present at the interface, which could be employed by electron-hole pair separation created by the absorption of incoming photons. The photovoltaic (PV) effect is the phenomenon of voltage and current generation in materials while they are illuminated. Non-centrosymmetric materials are made up of only a single component. But a photocurrent is an electric current that can also be made when there is no built-in potential It is highly desirable for exploring and discovering new materials and outcome-based approaches to exceed the Shockley-Queisser limit for singlejunction photovoltaic cells. Low-dimensional piezoelectric materials have the potential to generate the optoelectronic phenomenon called the bulk photovoltaic effect, which is not limited by the theoretical limit for solar radiation into electricity conversion. The recent development of 2D materials has demonstrated that by using the bulk photovoltaic effect (BPVE) for crystals lacking inversion symmetry, it is possible to overcome this limit. So far, the exploration of p-n junction designs has been addressed in several review articles. However, the mechanism of BPVE differs from traditional p-n junctionbased photovoltaics in 2D materials. In this focused review, various concepts regarding the shift-current response are explored, both from theoretical and experimental points of view, which are generated in the framework of deformed 2D materials. Finally, prospective approaches for building BPVEbased next-generation solar cells using ultrathin 2D materials are presented. These materials are expected to work better than current methods of turning energy into electricity.

Two-dimensional (2D) graphene oxide (GO) and molybdenum disulfide (MoS2) nanosheets (NSs) have been widely used as photothermal agents and as potential carriers of antitumor drugs. Their spatial thermal effects have been extensively explored for use at physiological and hyperthermic temperatures (37 to 46 °C). Furthermore, the modulation of the spatial thermal distributions with these NSs may have even more profound applications in the microstructural control of biomaterials at cryogenic temperatures (-196 to 37 °C). These applications include bioinspired microfabrication via freezing, food and drug freeze-drying, and biomaterial cryopreservation. However, such thermal effects of NSs and their applications at cryogenic temperatures had never been fully explored. Therefore, in this study, we have utilized the near-infrared laser induced photothermal effects of GO and MoS2 NSs to suppress the ice nucleation and ice crystal growth during warming of the biosamples. Using this approach, biological cells subjected to fast cooling to a deeply frozen state (-196 °C) were successfully recovered with high survival rates and full biological functionality. Thus, we provide a NS based effective approach to control the crystallization behaviors of water during warming at cryogenic temperatures, as NSs may have wide applications in both materials science and bioengineering.