This article presents a study on enhancing the phase transition temperature (Tc) in molecular ferroelectrics through hydrogen bond modification. The researchers introduced a hydroxyl group to modify hydrogen bonds, which significantly increased the Tc of the molecular ferroelectric 1-hydroxy-3-adamantanammonium tetrafluoroborate [(HaaOH)BF4] by at least 336 K. This resulted in a Tc of 528 K, much higher than that of barium titanate (BTO, 390 K). The material maintained ferroelectricity until its decomposition temperature, demonstrating stable ferroelectric domains. The study highlights the effectiveness of hydrogen bond modification in designing molecular ferroelectrics with high Tc and stable domains. The organic molecule with multiple modification sites and precise crystal engineering provides a pathway to develop high-Tc ferroelectrics with diverse properties. The research also shows that the material can be used in piezoelectric energy-harvesting devices, capable of lighting up LEDs and sensing mechanical stimuli. The findings suggest that hydrogen bond modification is a promising strategy for improving the performance of molecular ferroelectrics. The study emphasizes the importance of molecular design and crystal engineering in achieving high-performance ferroelectric materials. The results demonstrate the potential of molecular ferroelectrics in various applications, including flexible electronics and energy harvesting. The research contributes to the development of advanced ferroelectric materials with enhanced properties and broader applications.This article presents a study on enhancing the phase transition temperature (Tc) in molecular ferroelectrics through hydrogen bond modification. The researchers introduced a hydroxyl group to modify hydrogen bonds, which significantly increased the Tc of the molecular ferroelectric 1-hydroxy-3-adamantanammonium tetrafluoroborate [(HaaOH)BF4] by at least 336 K. This resulted in a Tc of 528 K, much higher than that of barium titanate (BTO, 390 K). The material maintained ferroelectricity until its decomposition temperature, demonstrating stable ferroelectric domains. The study highlights the effectiveness of hydrogen bond modification in designing molecular ferroelectrics with high Tc and stable domains. The organic molecule with multiple modification sites and precise crystal engineering provides a pathway to develop high-Tc ferroelectrics with diverse properties. The research also shows that the material can be used in piezoelectric energy-harvesting devices, capable of lighting up LEDs and sensing mechanical stimuli. The findings suggest that hydrogen bond modification is a promising strategy for improving the performance of molecular ferroelectrics. The study emphasizes the importance of molecular design and crystal engineering in achieving high-performance ferroelectric materials. The results demonstrate the potential of molecular ferroelectrics in various applications, including flexible electronics and energy harvesting. The research contributes to the development of advanced ferroelectric materials with enhanced properties and broader applications.