Highly crystallized ZnO–Ga2O3 core–shell heterostructure microwire is synthesized by a simple one‐step chemical vapor deposition method, and constructed into a self‐powered solar‐blind (200–280 nm) photodetector with a sharp cutoff wavelength at 266 nm. The device shows an ultrahigh responsivity (9.7 mA W−1) at 251 nm with a high UV/visible rejection ratio (R251 nm/R400 nm) of 6.9 × 102 under zero bias. The self‐powered device has a fast response speed with rise time shorter than 100 µs and decay time of 900 µs, respectively. The ultrahigh responsivity, high UV/visible rejection ratio, and fast response speed make it highly suitable in practical self‐powered solar‐blind detection. Additinoally, this microstructure heterojunction design method would provide a new approach to realize the high‐performance self‐powered photodetectors.

A novel type of hierarchical nanocomposites consisted of MoS2 nanosheet coating on the self-ordered TiO2 nanotube arrays is successfully prepared by a facile combination of anodization and hydrothermal methods. The MoS2 nanosheets are uniformly decorated on the tube top surface and the intertubular voids with film appearance changing from brown to black color. Anatase TiO2 nanotube arrays (NTAs) with clean top surfaces and the appropriate amount of MoS2 precursors are key to the growth of perfect compositing TiO2 @MoS2 hybrids with significantly enhanced photocatalytic activity and photocurrent response. These results reveal that the strategy provides a flexible and straightforward route for design and preparation nanocomposites based on functional semiconducting nanostructures with 1D self-ordered TiO2 NTAs, promising for new opportunities in energy/environment applications, including photocatalysts and other photovoltaic devices.

A high sensitivity self-powered solar-blind photodetector is successfully constructed based on the polyaniline/MgZnO bilayer. The maximum responsivity of the photodetector is 160 μA W at 250 nm under 0 V bias. The device also exhibits a high on/off ratio of ≈10 under 250 nm illumination at a relatively weak light intensity of 130 μW cm without any power.

Developing efficient and affordable catalysts is of great significance for energy and environmental sustainability. Heterostructure photocatalysts exhibit a better performance than either of the parent phases as it changes the band bending at the interfaces and provides a driving force for carrier separation, thus mitigating the effects of carrier recombination and back‐reaction. Herein, the photo/electrochemical applications of a variety of metal sulfides (MSx) (MoS2, CdS, CuS, PbS, SnS2, ZnS, Ag2S, Bi2S3, and In2S3)/TiO2 heterojunctions are summarized, including organic degradation, water splitting, and CO2 reduction conversion. First, a general introduction on each MSx material (especially bandgap structures) will be given. Then the photo/electrochemical applications based on MSx/TiO2 heterostructures are reviewed from the perspective of light harvesting ability, charge carrier separation and transportation, and surface chemical reactions. Special focus is given to CdS/TiO2 and PbS/TiO2‐based quantum dot sensitized solar cells. Ternary composites by taking advantages of positive synergetic effects are also well summarized. Finally, conclusions are made regarding approaches for structure design, and the authors' perspective on future architectural design and electrode construction is given. This work will make up the gap for TiO2 nanocomposites and shed light on the fabrication of more efficient MSx‐metal oxide junctions in photo/electrochemical applications.

A feasible strategy for hybrid photodetector by integrating an array of self-ordered TiO nanotubes (NTs) and selenium is demonstrated to break the compromise between the responsivity and response speed. Novel heterojunction between the TiO NTs and Se in combination with the surface trap states at TiO help regulate the electron transport and facilitate the separation of photogenerated electron-hole pairs under photovoltaic mode (at zero bias), leading to a high responsivity of ≈100 mA W at 620 nm light illumination and the ultrashort rise/decay time (1.4/7.8 ms). The implanting of intrinsic p-type Se into TiO NTs broadens the detection range to UV-visible (280-700 nm) with a large detectivity of over 10 Jones and a high linear dynamic range of over 80 dB. In addition, a maximum photocurrent of ≈10 A is achieved at 450 nm light illumination and an ultrahigh photosensitivity (on/off ratio up to 10 ) under zero bias upon UV and visible light illumination is readily achieved. The concept of employing novel heterojunction geometry holds great potential to pave a new way to realize high performance and energy-efficient optoelectronic devices for practical applications.

Single-site cocatalysts engineered on supports offer a cost-efficient pathway to utilize precious metals, yet improving the performance further with minimal catalyst loading is still highly desirable. Here we have conducted a photochemical reaction to stabilize ultralow Pt co-catalysts (0.26 wt%) onto the basal plane of hexagonal ZnIn2S4 nanosheets (PtSS-ZIS) to form a Pt-S3 protrusion tetrahedron coordination structure. Compared with the traditional defect-trapped Pt single-site counterparts, the protruding Pt single-sites on h-ZIS photocatalyst enhance the H2 evolution yield rate by a factor of 2.2, which could reach 17.5 mmol g−1 h−1 under visible light irradiation. Importantly, through simple drop-casting, a thin PtSS-ZIS film is prepared, and large amount of observable H2 bubbles are generated, providing great potential for practical solar-light-driven H2 production. The protruding single Pt atoms in PtSS-ZIS could inhibit the recombination of electron-hole pairs and cause a tip effect to optimize the adsorption/desorption behavior of H through effective proton mass transfer, which synergistically promote reaction thermodynamics and kinetics.

The ASC devices generally consist of a cathode as the energy source and an anode as the power source. Activated carbon is the most widely used materials as anode for ASC because of high specifi c surface area (SSA), excellent chemical stability, moderate cost, and high conductivity. However, most of commercial porous activated carbon usually exhibit poor rate performance because of the insuffi cient ion diffusion within the micropores, which limits their energy density (5-8 Wh kg −1 ) and power density. [ 11,12 ] The second-order structure of meso/macropores is essential to be induced. Thus, hierarchically porous carbons (HPCs) with rational distribution of interconnected macro, meso, and micropores are highly desired to replace currently used activated carbon. Recently, considerable research efforts have been devoted to develop various hierarchically porous carbon materials such as macro/mesoporous graphene framework, [13][14][15] porous graphene/carbon nanotube paper, [ 16 ] and nitrogen-doped porous carbon [ 17,18 ] as the electrodes. Nevertheless, the graphene, carbon nanotube (CNT), and nitrogen sources (e.g., polyaniline and polypyrrole) were used as precursors to prepare 3D porous carbon frameworks, which usually involved expensive/complex fabrication processes and were unfriendly to the environment, hindering the large area production for practical application. To obtain advanced electrode materials with optimized pore architectures in a facile and economic way, biomass as a biorenewable source can be directly carbonized as precursors to develop HPCs with high effi ciency and ease of processability. [ 19 ] Moreover, the biomass carbon retains the framework of the porenetworks with high SAAs and desired pore size and shape. To date, many natural materials have been used to develop HPCs with excellent chemical capacitive performance via an easy, effective, and low-cost strategy, such as hemp, [ 20 ] willow catkins, [ 21,22 ] lignin, [ 23 ] wheat fl our, [ 24 ] and rice bran, [ 25,26 ] In particular, ≈700 million tons of wheat are produced worldwide every year, while up to 14.4 million tons of wheat fl our were wasted because of over processing in China, making them one of the best candidates for supercapacitors. Wheat fl our consisting of starch (72%-80%) and protein (8-10%) can be well dispersed in distilled water to form suspension through vigorous stirring, and then form interconnected porous carbon Hierarchically porous nitrogen-doped carbon (HPC)/polyaniline (PANI) nanowire arrays nanocomposites are synthesized by a facile in situ polymerization. 3D interconnected honeycomb-like HPC was prepared by a costeffective route via one-step carbonization using urea and alkali-treated wheat fl our as carbon precursor with a high specifi c surface area (1294 m 2 g −1 ). The specifi c capacitances of HPC and HPC/PANI (with a surface area of 923 m 2 g −1 ) electrode are 383 and 1080 F g −1 in 1 M H 2 SO 4 , respectively. Furthermore, an asymmetric supercapacitor based on HPC/PANI as positive electrode and HPC as n...

In this article, we report a facile electrochemical method to modify anatase TiO 2 by cathodically biasing TiO 2 in an ethylene glycol electrolyte. The resulting black TiO 2 is highly stable with a significantly narrower bandgap and higher electrical conductivity. Furthermore, largely improved photoconversion efficiency (increased from 48% to 72% in the visible region, and from nearly 0% to 7% in the UV region), photocatalytic efficiency, and charge-storage capability ($42 fold increase) are achieved for the treated TiO 2 .