PVs) [1] and optoelectronic devices. [2] The power conversion efficiencies (PCE) of perovskite solar cells have exceeded 25% [3] in a few years since the first perovskite photovoltaics with a PCE of 3.9% came out in 2009. [4] The remarkable performance is attributed to the superior properties of perovskites such as a high and balanced carrier mobility, [5] long carrier diffusion length, [6] and large light absorption coefficient in the UV-vis range. [7] Meanwhile, metal halide perovskites in the form of colloidal nanocrystals (NCs) have drawn considerable attention in recent years. [8] Perovskite NCs could be easily synthesized at room temperature and ambient conditions with a large yield. [9] Besides, these colloidal perovskite NCs feature a number of advantages such as a high photoluminescence (PL) quantum yield, [10] narrow-band emission, [11] and tunable emission over the whole visible region. [12] Benefiting from these fascinating characteristics, perovskite NCs present promise in applications such as solutionprocessed photodetectors, [13] light-emitting diodes, [14] and solar cells. [15] Perovskite NCs have also been reported to demonstrate potential as photocatalysts due to the proper energy band structure, excellent visible-light responses, and high specific surface area. [16] Nevertheless, due to the presence of large amount of crystal boundaries in NCs film that greatly restricted charge and/or energy transfer, [17] improvement of photogenerated carriers transfer at the NC interface is necessary for applications such as photoelectric conversion and photocatalysis. [16b,18] Recently, heterostructures based on perovskites NCs and 2D materials (black phosphorus, reduced graphene oxide, graphitic carbon nitride, hexagonal boron nitride, and so on) have attracted much attention. [16b,18a,19] Due to the effective protection afforded by 2D nanosheets, the stability of perovskite NCs against air, moisture, and thermal conditions has been significantly enhanced. [19e,f ] Moreover, 2D nanosheets act not only as flexible substrates that connect dispersed perovskite nanocrystals but also enable the effective charge and/or energy transfer transport through the heterostructure interfaces. For example, Xu and co-workers reported the decoration of CsPbBr 3 NCs on porous g-C 3 N 4 nanosheets to construct the composite photocatalysts via N-Br chemical bonding. [19c] The unique N-Br bonding state leads to enhanced charge separation between the two materials. As expected, the resultant composite photocatalyst The performance of perovskite nanocrystals (NCs) in optoelectronics and photocatalysis is severely limited by the presence of large amounts of crystal boundaries in NCs film that greatly restricts energy transfer. Creating heterostructures based on perovskite NCs and 2D materials is a common approach to improve the energy transport at the perovskite/2D materials interface. Herein, methylamine lead bromide (MAPbBr 3 , MA: CH 3 NH 3 + ) perovskite NCs are homogeneously deposited on highly conductive few-layer MX...

All-inorganic perovskite nanocrystals (CsPbX3, X = Cl, Br, and I) have attracted increasing attention in various fields due to their unique optoelectronic properties. However, the vulnerable structure of CsPbX3 in aqueous solutions severely limits its further application in diverse fields. Although many protocols have been developed, the synthesis of all-inorganic CsPbX3 nanocrystals in a large-scale and environment-friendly manner remains a significant challenge. Here, we demonstrate a facile strategy for modifying CsPbX3 with a zeolitic imidazolate framework (ZIF-8) through mechanical milling, which can be used for the large-scale synthesis of CsPbX3@ZIF-8 composites. More importantly, the as-prepared composites display superior stability, and the photoluminescence (PL) intensity remains ∼86.7% after 8 weeks. Detailed characterizations indicate that the synergy in the composites can significantly facilitate the separation of photoinduced electrons and holes, leading to an increase in the photocurrent intensity. For photocatalytic H2 evolution under visible light, the optimal CsPbBr3@ZIF-8 composite exhibits a H2 productivity of 19.63 μmol·g–1 H2 after 2.5 h, thus proving to be a promising catalyst for photocatalytic H2 evolution under visible light in aqueous solutions. This work may not only provide a facile strategy for the modification of CsPbX3 nanocrystals but also promotes their practical applications in diverse fields.

The rapid development of portable and wearable electronics has promoted the integration of multifunction techniques. Although flexible energy storage systems have been successfully investigated, the compact configuration with photodetector and energy storage components has received less attention. As a new member of the 2D material class, MXene exhibits remarkable electronic and optical properties. Here, through the intentional introduction of ZIF-67 derivatives deposited on the Mo2CT x nanosheets, the synthesized Co-CoO x /NC/Mo2CT x heterostructure not only provided a straightforward pathway for photogenerated electrons to transport but also enhanced the structural stability of Mo2CT x , leading to a high responsivity and short rise/decay time under the illumination of simulated light in the photoelectrochemical (PEC) configuration. The integrated flexible device based on a zinc ion battery and Co-CoO x /NC/Mo2CT x heterostructure shows outstanding photodetection function and retains the intrinsic charge/discharge behaviors, which could monitor 1 day sunlight changes in real time. The paradigm presented here paves the way for realizing the development of miniaturization and multifunction toward next-generation portable and wearable technologies.

The development of safe, efficient, and non-noble-metal electrocatalysts is a promising approach for hydrogen energy production. However, due to low electrical conductivity and weak stability, non-noble metal catalysts for HER are significantly limited in practice. Here, a method for low-cost catalysts was reported for synthesizing Mo-CoP/Ti 3 C 2 T x composites in which Mo-doped CoP materials were facilely grown on the surface of Ti 3 C 2 T x MXene. The introduction of MXene and the doping of Mo promoted electron transfer and increased the active sites compared with CoP. As HER electrocatalysts, the Mo-CoP/Ti 3 C 2 T x materials exhibited a good HER activity with a low overpotential of only 117 mV. What's more, these catalysts had shown excellent electron conductivity, fast catalytic dynamics, and a boosted electrochemical active surface. Suitable synthetic ratios were obtained by optimizing the MXene substrate and the Mo doping amount. This work provided a new guide for the design and exploration of MXene based electrocatalysts.