A weak acid selective etching strategy was put forward to fabricate oxide-based hollow nanoparticles (HNPs) using core/shell nanostructures of active metal/oxide nanoparticles as sacrificial templates. ZnO-based HNPs, including pure ZnO, Au/ZnO, Pt/ZnO, and Au/Pt/ZnO HNPs with diameter below 50 nm and shell thickness below 6 nm has been first achieved at low temperature. The diameter, thickness, and even sizes of ZnO and noble metal ultrafine crystals of HNPs can be well adjusted by the etching process. Synchronous with the formation of HNPs, the internal metal−semiconductor interfaces can be controllably eliminated (Zn−ZnO) and reconstructed (noble metal−ZnO). Excitingly, such microstructure manipulation has endued them with giant improvements in related performances, including the very strong blue luminescence with enhancement over 3 orders of magnitude for the pure ZnO HNPs and the greatly improved photocatalytic activity for the noble metal/ZnO HNPs. These give them strong potentials in relevant applications, such as blue light emitting devices, environment remediation, drug delivery and release, energy storage and conversion, and sensors. The designed fabrication procedure is simple, feasible, and universal for a series of oxide and noble metal/oxide HNPs with controlled microstructure and improved performances.

Influence of light exposure on cesium lead halide nanostructures has been explored. A discovery of photon driven transformation (PDT) in 2D CsPbBr3 nanoplatelets is reported, in which the quantum‐confined few‐monolayer nanoplatelets will convert to bulk phase under very low irradiation intensity (≈20 mW cm−2). Benefiting from the remarkable emission color change during PDT, the multicolor luminescence photopatterns and facile information photo‐encoding are established.

Localized surface plasmon resonance (LSPR) has many applications which require meeting specific wavelength windows. The most prominent examples are photothermal therapy in biology, matched to the biological window (650–1350 nm), and communication relying on photodetection in optoelectronics, matched to the communication window (1260–1675 nm). However, for the classic noble metals (Au, Ag), tuning LSPRs from visible region to these two windows is still a demanding task due to their intrinsic limitations on charge density and dielectric function. Here, the discovery of near‐infrared biological and communication window‐matched plasmonic properties of semimetal TiS2 nanosheets (NSs) is reported for the first time. Developed synthesis procedures allow fine‐tuning width and thickness of single‐crystal TiS2 NSs. During characterization a new and intensive absorption peak in the 1000–1400 nm range is observed from both TiS2 NS colloid solutions and films. This peak is attributed to LSPR due to its dependence on particle shape and on the refractive index of solvents. The superiority of such LSPRs is demonstrated in both, biological and optical applications: excitation at 808 and 980 nm generates a ≈50 °C photothermal temperature rise, while excitation at 1310 nm results in two‐times enhanced photocurrents of PbS photodetectors compared to untreated devices.

A strong violet photoluminescence (PL) band at 425nm (2.92eV) was observed from the ZnO shell layer of the Zn∕ZnO core-shell nanoparticles prepared by laser ablation in liquid media. Such violet PL decreases with increase of the shell thickness or annealing temperature, showing good controllability. Based on the electron paramagnetic resonance measurements, the violet emission is attributed to the electronic transition from the defect level, corresponding to high-concentration zinc interstitials, to the valence band. This study is in favor to clarify the defect-related emissions and to extend the optical and electronic applications of nanostructured ZnO.

As an important energy‐saving technique, white‐light‐emitting diodes (W‐LEDs) have been seeking for low‐cost and environment‐friendly substitutes for rare‐earth‐based expensive phosphors or Pd2+/Cd2+‐based toxic quantum dots (QDs). In this work, precursors and chemical processes were elaborately designed to synthesize intercrossed carbon nanorings (IC‐CNRs) with relatively pure hydroxy surface states for the first time, which enable them to overcome the aggregation‐induced quenching (AIQ) effect, and to emit stable yellow‐orange luminescence in both colloidal and solid states. As a direct benefit of such scarce solid luminescence from carbon nanomaterials, W‐LEDs with color coordinate at (0.28, 0.27), which is close to pure white light (0.33, 0.33), were achieved through using these low‐temperature‐synthesized and toxic ion‐free IC‐CNRs as solid phosphors on blue LED chips. This work demonstrates that the design of surface states plays a crucial role in exploring new functions of fluorescent carbon nanomaterials.